Internal Use

2021

高橋 賢, “準天頂衛星みちびきから放送される災害・危機通報のメッセージ有効期間分布,” 電子情報通信学技術研究報告, CS2021-55, Oct. 2021.
Satoshi Takahashi, “Message effective duration distribution of disaster and crisis management report sent from quasi-zenith satellite Michibiki,” IEICE Technical Report, CS2021-55, Oct. 2021.
URL: https://www.ieice.org/ken/paper/202110145C56/

準天頂衛星みちびきは,衛星測位のための信号のみならず,測位精度を高める補強メッセージ信号や,災害や危機に関するメッセージ信号をも放送している.一方,移動受信機においては,信号遮蔽やフェージングにより,すべてのメッセージが受信可能であるとは限らない.このようなメッセージ受信失敗に対し,この災害・危機管理通報においては,同一メッセージが複数回にわたり継続的に送信される.そのために,受信機においては,一定期間だけ休眠した後に受信機を起動して,再び休眠する間欠受信を適用して,電池寿命を延ばすことも考えられる.ここでは,みちびきの過去のメッセージアーカイブを用いて,災害・危機管理通報メッセージの継続時間や,そのメッセージ送出間隔を調査したので報告する.
The quasi-zenith satellite Michibiki broadcasts not only signals for satellite positioning, but also augmentation message signals that improve positioning accuracy and message signals to prompt disasters and crises. On the other hand, in the mobile receiver, not all the messages can be received due to signal obstruction and fading. In response to such message reception failure, the same message is continuously transmitted multiple times in this disaster and crisis management report. Therefore, in the receiver, it is conceivable to start the receiver after sleeping for a certain period of time and apply intermittent reception to sleep again to extend the battery life. Here, we report the duration of the disaster and crisis management report message and the message transmission interval using Michibiki's past message archive.

高橋 賢, “準天頂衛星みちびきが放送する災害・危機通報の相互情報量,” 電子情報通信学会総合大会, B-8-19, March 2021.
Satoshi Takahashi, “Mutual information of disaster and crisis report broadcast from quasi-zenith satellite Michibiki,” IEICE General Conference, B-8-19, March 2021.

準天頂衛星みちびきが放送する災害・危機通報信号を電池寿命に限りのある移動受信機にて間欠受信するために,その相互情報量を考察した.自らに関する災害・危機通報が発生することは稀であるために間欠受信は有効であると考えられる一方,受信機休眠中に自らに関するDC通報が放送されると情報欠損をもたらす.伝送路を非対称無記憶2元通信路に近似して求めた相互情報量は,そのデューティ比にほぼ比例した.災害・危機通報通報の単純な間欠受信は,そのデューティ比だけの相互情報量低下をもたらすため,むしろ,過去のDC通報内容の活用が必要である.
In order to intermittently receive the disaster and crisis management report signal broadcast from the quasi-zenith satellite Michibiki with a mobile receiver with a limited battery life, the amount of mutual information is examined. Intermittent reception is considered to be effective because the disaster and crisis management reports to oneself rarely occur, but it causes information loss when a disaster and crisis management report for oneself is broadcast while the receiver is in sleep state. The mutual information obtained approximating the transmission diagram with an asymmetric non-memory binary channel was almost proportional to its duty ratio. Since the simple intermittent reception of the disaster and crisis report management reports lead to a decrease in the amount of mutual information corresponding to the duty ratio, it is rather necessary to utilize the contents of past disaster and crisis management reports.

2020

高橋 賢, “[招待講演]準天頂衛星みちびきが放送する災害・危機通報の相互情報量解析による間欠受信方法,” 電子情報通信学技術研究報告, ICD2020-12, Aug. 2020.
Satoshi Takahashi, “[Invited Talk] An intermittent reception with mutual information analysis of disaster and crisis report broadcast from quasi-zenith satellite Michibiki,” IEICE Technical Report, ICD2020-12, Aug. 2020.
URL: https://www.ieice.org/ken/paper/20200807X1Zp/

日本の内閣府が運用する準天頂衛星「みちびき」は,GPS衛星が放送する測位信号とほぼ同等の測位信号を放送するのみならず,災害・危機通報信号をも放送する.一方,自らに関する災害・危機通報が発生する可能性は一般に低いと考えられる.そのため,災害・危機通報信号を移動受信する利用者は,稀にしか関係しない災害危機事態の通報を連続的に受信するのではなく,一定期間だけ受信して,残りの期間を休眠する間欠受信を用いて,平均消費電力を低減することを望むであろう.本報告では,受信機に対してその通報に含まれる24ビットCRCを用いて選択受信を行うことを提案し,その間欠受信パラメータを相互情報量から推定する.
The quasi-zenith satellite Michibiki, operated by the Cabinet Office of Japan, not only broadcasts navigation signals that are almost the same as the navigation signals broadcast by GPS satellites, but also sends disaster and crisis report signals. On the other hand, the occurrence probability of issuing a disaster and crisis report related to a user would be low. Therefore, a mobile user would like to receive the signals intermittently rather than continuously because of the rare occurrence probability of disaster. The intermittent reception, in which the signal is received for a certain period and the rest period is put to sleep, also enables the users to reduce the average power consumption. In this report, an intermittent reception method that the receiver performs selective reception using the 24-bit CRC included in the message is proposed and is evaluated using the mutual information.

Satoshi Takahashi, “Determining broadcaster advised emergency wake-up signal with switching two detection methods and observing several TMCC frames for mobile ISDB-T receivers,” ITE Transactions on Media Technology and Applications, vol.8, no.3, pp.126-131, July 2020. DOI: 10.3169/mta.8.126.
URL: https://www.jstage.jst.go.jp/article/mta/8/3/8_126/_article/-char/en

When in an emergency, an ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) broadcaster would send a special signal to wake-up their receivers. However, the mobile receivers would wrongly determine the wake-up signal due to the erroneous radio channel. The mobile receivers also need reducing the power consumption when in idle because they are generally battery-operated. In this paper, a method of reliably determining the wake-up signal while reducing the power consumption is proposed. The method uses switching two detection methods and determining the wake-up signal with a certain time observation. The evaluation is conducted in terms of the mutual information to be obtained from the receiver. The combination of the detection method and the determination method maximizes the mutual information.

高橋 賢, “準天頂衛星みちびきから放送される災害・危機通報のヌルメッセージを活用した間欠受信方法,” 電子情報通信学会論文誌, vol.J103-B, no.5, pp.206-209, May 2020. DOI: 10.14923/transcomj.2019JBL4013.
Satoshi Takahashi, “An intermittent reception of disaster and crisis management report sent from quasi-zenith satellites Michibiki with null messages,” IEICE Transactions on Communications, vol.J103-B, no.5, pp.206-209, May 2020. DOI: 10.14923/transcomj.2019JBL4013.

準天頂衛星みちびきは,測位信号だけでなく,災害・危機通報をも放送しているが,平時の受信機はその放送タイミングが未知であるために,そのままでは間欠受信できない.ここでは,平時に放送されるヌルメッセージに着目して,その間欠受信方法を提案する.
The quasi-zenith satellite "Michibiki" broadcasts positioning signals and the disaster-and-crisis report. However, the receivers cannot receive this report intermittently because when this report will be sent is unknown to them. In this letter, a method of the intermittent reception is proposed using the characteristic of the null messages.

高橋 賢, “小さなデータを低消費電力でより遠くまで届けるLPWA,” 電子情報通信学会総合大会, CI-5-6, March 2020.
Satoshi Takahashi, “LPWA as a radio that conveys small data with a lower power consumption,” IEICE General Conference, CI-5-6, March 2020.

黎明期の無線通信は情報を遠くまで伝達することを目指してきた.陸上移動無線通信の利用が一般化した今,数十バイト程度の小さな情報を,より低消費電力で,そしてより安価に遠方まで伝達するLPWA(Low-Power Wide-Area)も望まれるようになった.本講演ではLPWAの基本原理,応用,そして課題について解説する.

2019

高橋 賢, “ISDB-T緊急警報放送信号の一定時間受信に基づく検出方法選択,” 映像情報メディア学会冬季大会, 14C-6, Dec. 2019.
Satoshi Takahashi, “Selection of determining methods of ISDB-T emergency warning signals with certain time reception,” ITE Winter Convention, 14C-6, Dec. 2019.

地上ディジタルテレビ方式ISDB-T(Integrated Services Digital Broadcasting-Terrestrial)方式にて伝送される緊急警報放送用の自動起動信号(以下,自動起動信号と略す)の存在を検出するために,2つの信号検出方法が提案されている.受信機において低消費電力かつ高信頼に自動起動信号の存在を判定するため,本稿では電波受信強度に応じてこれらの検出方法を切り替え,また,それぞれの受信方法において一定時間観測結果から自動起動信号の存在を判定することを提案する.
For detecting an emergency wake-up signal sent from the ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) broadcaster, two detection methods have been proposed for the receiver. This article proposes switching these detection methods with the signal strength and determining it with a certain time observation for reducing power consumption while enhancing reliability.

高橋 賢, “ISDB-Tテレビ受信機における複数TMCCフレーム観測に基づく自動起動信号の検出,” 映像情報メディア学会誌, vol.73, no.6, pp.1168-1171, Nov. 2019. DOI: 10.3169/itej.73.1168.
Satoshi Takahashi, “Detecting emergency wake-up signal based on observation of several TMCC frames for ISDB-T television receivers,” The Journal of The Institute of Image Information and Television Engineers, vol.73, no.6, pp.1168-1171, Nov. 2019. DOI: 10.3169/itej.73.1168.
URL: https://www.jstage.jst.go.jp/article/itej/73/6/73_1168/_article/-char/ja

ISDB-Tテレビ受信機において,緊急自動起動信号を検出したときの起動条件を考察する.この起動信号情報は,放送局が約0.2秒ごとにくり返し放送する制御信号上にあり,緊急状態を示す1ビット情報である.移動テレビ受信機は,フェージングのために,その起動信号を誤って受信する可能性がある.そこで,継続する複数の起動信号情報を受信機にて観測して,一定数以上の起動信号を検出したときに起動することを提案する.受信機が得られるであろう相互情報量から,この起動しきい値を考察する.
English abstract is available.

岩本 滉希, 藤崎 宏史, 高橋 賢, 田中 公一, 藤原 真, 八方 直久, “仰角マスク角度によるGNSS単独測位とMADOCA測位の距離差依存性,” 電子情報通信学会技術研究報告, CS2019-63, Oct. 2019.
Koki Iwamoto, Hiroshi Fujisaki, Satoshi Takahashi, Koichi Tanaka, Makoto Fujiwara, and Naohisa Happo, “Dependence of elevation mask angle on distance difference between GNSS single positioning and MADOCA positioning,” IEICE Technical Report, CS2019-63, Oct. 2019.
URL: https://www.ieice.org/ken/paper/20191031g1R3/

準天頂衛星「みちびき」の測位補強信号MADOCAは他衛星を含む精度の高い衛星補正情報を放送している。しかしながら直接受信することはまだ一般的ではない。一方GNSS単独測位の仰角マスクが小さいと地表構造物によるマルチパスにより、また仰角マスクが大きい可視衛星数減少により、測位精度が低下すると考えられる。本論文では、MADOCA測位結果を基準として単独測位の最適な仰角マスク角を実験的に求める。
The Augmentation signal MADOCA the quasi-zenith satellites "Michibiki" broadcast provides correct information not only for Michibiki but also for GPS and so on. However, commercial receivers of receiving the augmentation signal care not widely available in the market. On the other hand, it is important to set the appropriate elevation mask angle. The receiver would ignore satellites below the angle. Decreasing in the elevation mask angle deteriorates the positioning accuracy due to multipath phenomenon causing surface structure such as building. An increasing in the elevation mask angle also worsens the accuracy because of diminishing the available satellite signals. In this paper, the optimal elevation mask angle for single positioning is experimentally obtained using on the MADOCA positioning.

高橋 賢, “準天頂衛星みちびきから放送される災害・危機通報の間欠受信方法の検討,” 電子情報通信学会技術研究報告, CS2019-62, Oct. 2019.
Satoshi Takahashi, “An intermittent reception method of disaster and crisis management report broadcasted from quasi-zenith satellites Michibiki,” IEICE Technical Report, CS2019-62, Oct. 2019.
URL: https://www.ieice.org/ken/paper/20191031r1qZ/

準天頂衛星「みちびき」は,GPSと同等のフォーマットによる測位信号を放送するのみならず,その測位精度を高める補強信号や,災害や危機に関する情報を伝達するメッセージ信号をも放送している.災害発生時において,その「災害・危機通報」は4秒に1度の頻度で放送されるために,利用者側では間欠受信が可能とされている.一方,平時においては,この災害・危機通報が放送されるタイミングが受信機に対して未知なので,そのままではその受信機に間欠受信を適用できない.本論文では,平時において放送される「ヌルメッセージ」に着目して,その間欠受信方法を提案する.
The quasi-zenith satellite "Michibiki" not only broadcasts positioning signals in the same format as GPS, but also broadcasts augmentation signals that improve positioning accuracy. The message signals also convey information about disasters and crises information. When a disaster occurs, the disaster and crisis report is broadcast once every 4 seconds, so the user can receive intermittently. However, it is hard to apply the intermittent reception in normal situations, because it is not possible for the receivers to know when this disaster and crisis report will be broadcast. In this report, the characteristic of ``null message'' the satellites broadcast during normal situation is considered and the intermittent reception method is proposed.

高橋 賢, “ISDB-Tテレビ受信機における緊急自動起動信号の一定時間観測,” 電子情報通信学会ソサイエティ大会, B-8-22, Sept. 2019.
Satoshi Takahashi, “Certain period observation of emergency wake-up signals for ISDB-T mobile television receivers,” IEICE Society Conference, B-8-22, Sept. 2019.

ISDB-Tテレビ放送信号に重畳される緊急警報用の自動起動信号は,約0.2秒ごとにくり返し放送さえる制御信号TMCC上にある.ここでは,受信機において連続する過去の複数TMCCを観測し,一定数以上の起動信号を検出したときに起動することを提案する.受信機が誤って起動信号ありと判断する誤警報確率,誤って起動信号を見逃す見逃し確率,および起動信号放送確率を仮定して,受信機が得られるであろう相互情報量を求めた.その結果,起動信号のより長い期間の観測により高い相互情報量が得られることが明らかになった.

岩本 滉希, 藤崎 宏史, 高橋 賢, 田中 公一, 藤原 真, 八方 直久, “GNSS単独測位とMADOCA測位の比較,” 電子情報通信学会ソサイエティ大会, B-2-8, Sept. 2019.
Koki Iwamoto, Hiroshi Fujisaki, Satoshi Takahashi, Koichi Tanaka, Makoto Fujiwara, and Naohisa Happo, “Comparison of results on GNSS standalone positioning and MADOCA positioning,” IEICE Society Conference, B-2-8, Sept. 2019.

準天頂衛星(QZSS)は測位精度を高める補強信号を提供している.この補強信号の1つであるMADOCA(Multi-GNSS Advanced Demonstration tool for Orbit and Clock Analysis)の補強効果を確認するため単独測位とMADOCA測位に比較をした.車の走行実験で測位に必要なデータを収集して後処理解析により測位を行った.比較した結果,単独測位と比べてMADOCA測位は車線スケールで信頼性の高い結果が継続的に得られることがわかった.

Satoshi Takahashi, “Transmission power control of terrestrial pseudolite signal for global navigation satellite systems,” IEICE Communication Express (ComEX), vol.8, no.8, pp.335-340, Aug. 2019. DOI: 10.1587/comex.2019XBL0058.

In global navigation satellite systems (GNSS), we need signals from more than four satellites to find out the location at the receiver. However, the satellite visibility is occasionally blocked especially in city areas. For augmenting the availability, placing the pseudo satellite, or pseudolite, has been proposed. A pseudolite broadcasts the signal in the same format as the satellites broadcast and acts as an additional satellite to the receiver. However, the satellite signals are often blocked by a pseudolite signal at the receiver in the close proximity to the pseudolite, and the phenomenon is referred to as the near-far problem. In this letter, a pseudolite with burst pulse transmission that the power varies pulse-to-pulse is proposed to mitigate the near-far problem.

高橋 賢, “ISDB-Tテレビ受信機における一定時間累積確率を考慮した自動起動信号の検出方法,” 電子情報通信学会技術研究報告, CS2019-44, July 2019.
Satoshi Takahashi, “A method of detecting wake-up signal considering cumulative time probability for ISDB-T television receivers,” IEICE Technical Report, CS2019-44, July 2019.
URL: https://www.ieice.org/ken/paper/20190705o1OX/

ISDB-Tディジタルテレビ受信機において,緊急自動起動信号を検出したときの起動条件について考察する.この起動信号情報は,放送局が約0.2秒ごとにくり返し放送する制御信号上にあり,緊急状態を示す1ビットの情報である.移動テレビ受信機は,しばしばその起動信号を誤って受信する可能性がある.そこで,継続する複数起動信号情報を受信機にて観測して,一定数以上の起動信号を観測したときに起動することを提案する.受信機が得られるであろう相互情報量から,この起動しきい値を考察する.
For ISDB-T digital television receivers, the condition the receiver wakes up due to detection of the emergency automatic activation signal is considered in this report. The activation signal information is a 1-bit information indicating an emergency state. It is on the control signal the broadcaster repeatedly sends about every 0.2 seconds. However, mobile television receivers often erroneously receive such activation signals. Therefore, observing plural activation signals information and determining the activation by a predetermined threshold of the number of activation signals at the receiver are proposed. This activation threshold is analyzed from the mutual information to be obtained by the receiver.

藤崎 宏史, 岩本 滉希, 高橋 賢, 田中 公一, 藤原 真, 八方 直久, “導電性ウェアhitoeを用いた運動時心電図のLPWA無線伝送方法の検討,” 電子情報通信学会技術研究報告, CS2019-33, July 2019.
Hiroshi Fujisaki, Koki Iwamoto, Satoshi Takahashi, Koichi Tanaka, Makoto Fujiwara, and Naohisa Happo, “A method of LPWA radio transmission of exercise electrocardiography with conductive sports wear hitoe,” IEICE Technical Report, CS2019-33, July 2019.
URL: https://www.ieice.org/ken/paper/20190704A1OX/

運動トレーニング時においては,運動強度を知るために,しばしば脈拍数が測定される.より詳細な情報を含む心電図や加速度情報をリアルタイムに計測して無線伝送できれば,新しいトレーニング方法が見出される可能性がある.ここでは導電性ウエアhitoeを用いて,安静時と運動時の心電図を計測し,またその特徴データをLPWA(Low Power Wide Area)無線伝送する方法について検討したので報告する.
During exercise training, the pulse rate is often measured to know exercise intensity. Wirelessly transmiting electrocardiograph and acceleration information in real time would enable us to discover a new training method. In this report, electrocardiograph at rest and exercise is measured using the conductive wear hitoe, and the method of transmitting the feature data of electrocardiograph with Low Power Wide Area (LPWA) radio transmission is considered with the results.

高橋 賢, “[招待講演]電波を用いた位置計測の特性,” 電子情報通信学会技術研究報告, CQ2019-23, May 2019.
Satoshi Takahashi, “[Invited Talk] Characteristics of positioning with radiowave,” IEICE Technical Report, CQ2019-23, May 2019.
URL: https://www.ieice.org/ken/paper/20190530z1mI/

電波を用いた位置計測実験の結果を報告する.本報告は,ドップラレーダによる屋内2次元位置推定,船舶自動識別装置(AIS: Automatic Identification System)情報の処理,およびGNSS(Global Navigation Satellite System)衛星電波を用いた測位の結果からなる.ドップラレーダによる位置推定では,受信電波強度のしきい値を変化させて人体までの距離を推定することを提案する.AIS情報処理においては,より標高の高い陸上船舶監視局がより遠くの船舶を検出できるとはいえないことを示し,またAIS情報から船舶が接近回避行動を行う距離を推定する.GNSS測位に関しては,市販受信モジュールを用いて,その測位精度を比較する.
In this report, results of positioning experiments using radiowaves are shown. This report consists of two-dimensional positioning in indoors using Doppler radar, processing of AIS (Automatic Identification System) information in which ships transmit their own position, and positioning experiments using GNSS (Global Navigation Satellite System) radiowaves. In positioning with Doppler radar, the distance estimation to the human body by changing the threshold of received radiowave intensity is proposed. In AIS information processing, result that a higher altitude of the ship monitoring station does not always provide the maximum detection distance is shown. With AIS information, the distance that ship would act collision avoidance action is estimated. For GNSS positioning, the positioning accuracy using commercial receiver modules is compared.

高橋 賢, “ISDB-Tテレビ受信機における自動起動信号の間欠受信特性,” 電子情報通信学会総合大会, B-8-12, March 2019.
Satoshi Takahashi, “Intermittent reception performance of automatic wake-up signal for ISDB-T television receivers,” IEICE General Conference, B-8-12, March 2019.
Loc: 早稲田大学西早稲田キャンパス(東京)
URL: http://www.ieice.org/jpn/event/program/2018G/Settings/ab/b_08_023.html

ISDB-T地上ディジタルテレビ放送信号に重畳される緊急警報放送用の自動起動信号を間欠受信する方法に対して,相互情報量の点で比較した.受信Eb/N0が7 dB以上のときには自動起動信号以降からTMCC先頭までのフレーム内期間を休眠する方法を,それ以下のときにはTMCCパリティのビットパターンを用いて自動起動信号の誤検出を軽減する方法にフレーム間での間欠受信を適用すれば,より高い相互情報量が得られることがわかった.
The method of intermittently receiving the automatic start signal for the emergency warning broadcast superimposed on the ISDB-T terrestrial digital television broadcast signal was compared in terms of the mutual information. It was found that a higher mutual information amount can be obtained by applying intermittent reception between frames of the in-frame period from the start of the automatic start signal to the beginning of the TMCC when the received Eb/N0 is more than 7 dB. On the other hand, the majority determination among TMCC bit pattern is used when the received Eb/N0 is less than 7 dB.

Satoshi Takahashi, “A method of determining broadcaster advised emergency wake-up signal for ISDB-T digital television receivers,” Journal of Telecommunications and Information Technology (JTIT), vol.2019, no.1, pp.103–112, March 2019. DOI: 10.26636/jtit.2019.131619.
URL: https://www.itl.waw.pl/en/publications/journal-jtit

There is a way of automatically waking up television receivers when a broadcaster advises an emergency alert. The emergency wake-up procedure is called an Emergency Warning System (EWS) in the Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) digital television standard. In ISDB-T, the special signal is in a control message called transmission and modulation configuration control (TMCC). However, wrong determination of the wake-up signal, often caused in mobile reception, leads to the unnecessary wake up. In this paper, a method of reliably determining a wake-up signal is proposed by assuming that broadcasters will not change the TMCC message except for the wake-up signal when the broadcaster advises an emergency alert. A change in the wake-up bit leads to variate the parity, and the proposed method also uses the variations. Mutual information to be obtained by the wake-up receiver is evaluated using the memoryless binary asymmetric channel model. Results showed the proposed method provided mutual information even at a Eb/N0 lower than 10 dB. Mutual information of the proposed method with the intermittent reception is also analyzed as a function of the duty ratio of an intermittent receiver.

2018

高橋 賢, 田中 公一, 藤原 真, 八方 直久, “異なる無線通信システム間信号の電力差計算方法,” 映像情報メディア学会技術報告, BCT2018-92, Nov. 2018.
Satoshi Takahashi, Koichi Tanaka, Makoto Fujiwara, and Naohisa Happo, “Calculation method of power difference among different radio communication systems,” ITE Technical Report, BCT2018-92, Nov. 2018.
Loc: 徳島大学
URL: https://www.ite.or.jp/ken/paper/20181129YAhf/

同一周波数で運用される複数無線局からの信号を同時に受信すると干渉が生じる.信号処理によりこのような干渉信号を除去しようとすると,所望信号にも影響を与えることがある.所望波と干渉波の両方の確率分布が与えられれば,確率分布の減算表現によりその正しく受信できる確率を表現できると考えられる.ここでは,特性関数法を用いてこの信号差の確率分布を求める.
If signals from multiple radio stations operating at the same frequency are simultaneously received, interference occurs. Attempting to remove such an interference signal by signal processing may also affect a desired signal. Given the probability distributions of both the desired wave and the interference wave, it can be considered that the probability of correct reception can be represented by subtraction representation of the probability distribution. Here, the probability distribution of this signal difference is obtained using the characteristic function method.

高橋 賢, “TMCCパリティ不一致数を用いたISDB-Tディジタルテレビ自動起動信号の間欠受信方法,” 電子情報通信学会技術研究報告, CS2018-62, Nov. 2018.
Satoshi Takahashi, “Intermittent reception of emergency wake-up signal on ISDB-T digital television broadcasting using TMCC parity disagreements,” IEICE Technical Report, CS2018-62, Nov. 2018.
Loc: 松山市立子規記念博物館
URL: https://www.ieice.org/ken/paper/2018110251H0/

ISDB-Tディジタルテレビには,緊急時において,放送局からの特別な信号により受信機を自動的にオンにしてニュース番組を表示する仕組みがある.一方,テレビ放送を移動受信する機器においては,低消費電力にてその緊急信号を受信できることが望まれている.ここでは,移動受信機が得られるであろう相互情報量をもとにして、間欠受信による低消費電力受信とより確実な緊急信号受信とのトレードオフを検討する.
In the ISDB-T digital television, there is a mechanism for automatically wake up the receiver to tune and show the news program in response to a special signal from the broadcaster in case of emergency. Meanwhile, a mobile receiver needs to catch the emergency signal with a lower power consumption. Based on the mutual information amount that mobile receivers would be able to obtain, we consider the trade-off between low-power consumption with intermittent reception and more reliable emergency signal reception in this report.

Satoshi Takahashi, “Mutual information analysis of broadcaster advised emergency automatic wake-up signals with intermittent reception,” IEICE Information and Communication Technology Forum (IEICE ICTF 2018), pp.1-5, Graz, July 2018. DOI: 10.34385/proc.32.SESSION01_1.
URL: https://www.ieice.org/publications/proceedings/summary.php?expandable=8&iconf=ICTF&session_num=SESSION01&number=SESSION01_1&year=2018

A television broadcaster would send a special signal to automatically wake up their receivers when in emergency. Such wake-up receivers are available around the world. In a mobile television receiver, however, the activation signal would be wrongly determined due to the reception errors. In addition, because a disaster rarely occurs, one would think the receiver does not provide useful information at all and it is better to make it sleep. In this paper, quantitative information to be obtained by the wake-up receiver is evaluated approximating the transmission channel of the activation signal from the broadcast station to the receiver to the asymmetric memoryless binary communication channel. On the other hand, battery capacity in a mobile receiver is limited and the intermittent reception would be used. Therefore this paper also analyses the mutual information as a function of the duty ratio of an intermittent receiver.

高橋 賢, “TMCCパリティの不一致数を用いたISDB-T緊急自動起動信号の低消費電力受信方法,” 映像情報メディア学会誌, vol.72, no.6, pp.J94-J97, June 2018. DOI: 10.3169/itej.72.J94.
Satoshi Takahashi, “A low consumption power reception method with TMCC parity disagreements for determining ISDB-T emergency automatic wake-up signals,” The Journal of The Institute of Image Information and Television Engineers, vol.72, no.6, pp.J94-J97, June 2018. DOI: 10.3169/itej.72.J94.
URL: https://www.jstage.jst.go.jp/article/itej/72/6/72_J94/_article/-char/ja

ISDB-T(Integrated Services Digital Broadcasting-Terrestrial)地上ディジタルテレビ方式では,緊急時に放送局が送信する特別な信号により,その受信機を自動的にオンにできる.この自動起動信号が伝送される伝送制御(TMCC: Transmission and Multiplexing Configure Control)情報にはパリティを含むが,このパリティを利用することでより高信頼に自動起動信号を判定する方法が提案されている.本速報では,このパリティを用いる方法において,受信したTMCC情報ビット列と自動起動信号の状態により決定されるTMCC情報ビット列とを比較して,その不一致数により自動起動信号状態の確からしさを判定することを提案し,さらにこの確からしさから消費電力を削減する受信方法を検討する.
English abstract is available.

高橋 賢, “間欠受信を行うISDB-T自動起動信号受信機における相互情報量の解析,” 電子情報通信学会総合大会, B-8-23, March 2018.
Satoshi Takahashi, “Analysis of mutual information for ISDB-T periodic automatic wake-up receivers,” IEICE General Conference, B-8-23, March 2018.
Loc: 東京電機大学(東京)
URL: http://www.ieice.org/jpn/event/program/2018G/Settings/ab/b_08_023.html

ISDB-T地上ディジタルテレビ放送信号に重畳される緊急警報放送用の自動起動信号を間欠受信するときの相互情報量を解析した.移動受信しながら,この自動起動信号を受信することを考える.このとき,ビット誤りにより,誤って自動起動信号を検出する可能性と,誤って自動起動信号を見逃す可能性とがある.これらは異なる特性を示すので,これは非対称通信路になる.その相互情報量を求めた結果,間欠受信による相互情報量の低下は電波強度の増大によっても回避できないことが明らかになった.
To appear.

高橋 賢, “ISDB-T緊急警報放送信号受信により得られる相互情報量の検出方法依存性,” 電子情報通信学会技術研究報告, CS2017-111, March 2018.
Satoshi Takahashi, “Dependence of determination methods on mutual information obtained from ISDB-T emergency warning signal reception,” IEICE Technical Report, CS2017-111, March 2018.
Loc: 九州大学西新プラザ(福岡県博多市)
URL: https://www.ieice.org/ken/paper/2018031331Dw/

テレビジョン伝送方式ISDB-Tでは,緊急時における放送局からの特別な信号によりその受信機を自動起動させることができる.この自動起動の原理は,電源オフの受信機においてもチューナ部を動作させ続けて,このような信号を待機受信することにある.一方,移動受信機においては,フェージングや受信機雑音に起因するビット誤りのために,放送された緊急信号に関する情報が失われる.ここでは,極めて発生確率が低いであろう警報放送確率と受信機におけるビット誤りから,この自動起動を誤る確率を非対称無記憶2元通信路にて表現して,その受信特性を解析する.
In an emergency, some ISDB-T television receivers would wake up themselves by receiving a broadcaster transmitted special signal. The mechanism waking up is that the tuner at the receiver continues work while the main power has turned off, and the tuner waits for the wake-up signal. On the other hand, bit error that fading and the receiver noise cause loses the information regarding the wake-up signal. In this report, the probability a receiver wrongly activated is analyzed approximating the mechanism to the asymmetric memoryless binary channel. The probability that a broadcaster advices an emergency and that would be rare, and the bit errors at the receiver are used in the approximation.

高橋 賢, “非対称無記憶2元通信路近似を用いたISDB-T自動起動信号に対する間欠受信特性解析,” 映像情報メディア学会技術報告, BCT2018-42, March 2018.
Satoshi Takahashi, “Performance analysis of periodic reception for ISDB-T automatic wake-up signal with asymmetric memoryless binary channel approximation,” ITE Technical Report, BCT2018-42, March 2018.
Loc: 平良港ターミナルビル(宮古島)
URL: https://www.ite.or.jp/ken/paper/20180309LA6N/

テレビジョン伝送方式ISDB-Tでは,緊急時における放送局からの特別な信号によりその受信機を自動起動させることができる.この自動起動の根本原理は,電源オフの受信機においてもチューナ部を動作させ続けて,この信号を待機受信することにある.一方,移動受信機においては,電源容量に限りのあることが多く,間欠的にこのチューナ部を起動することが望まれている.ここでは,極めて発生確率が低いであろう警報放送確率と,チューナ部起動のデューティ比,および受信機におけるビット誤りから,この自動起動を誤る確率を非対称無記憶2元通信路にて表現して,その間欠待機受信機の受信特性を解析する.
In an emergency, some ISDB-T television receivers would wake up themselves by receiving a broadcaster transmitted special signal. The mechanism waking up is that the tuner at the receiver continues work while the main power has turned off, and the tuner waits for the wake-up signal. On the other hand, battery capacity in a mobile receivers would be limited and the tuner would be activated periodically. In this report, the probability a receiver wrongly activated is analyzed approximating the mechanism to the asymmetric memoryless binary channel. The probability that a broadcaster advices an emergency and that would be rare, the duty ratio the receiver wakes up, and the bit errors at the receiver are used in the approximation.

高橋 賢, 田中 公一, 藤原 真, 八方 直久, “特性関数法によるレイリーフェージング環境での捕捉効果の解析,” 映像情報メディア学会技術報告, BCT2018-23, Jan. 2018.
Satoshi Takahashi, Koichi Tanaka, Makoto Fujiwara, and Naohisa Happo, “Analysis of capture effect in Rayleigh fading environments with characteristic function method,” ITE Technical Report, BCT2018-23, Jan. 2018.
Loc: 長崎大学雲仙Eキャンレッジ交流センタ(長崎市)
URL: https://www.ite.or.jp/ken/paper/20180119LA67/

同一周波数の複数無線信号を同時に受信するとき,それらのうちで最も強度の大きい信号のみが復調され,その他の信号が抑圧されることがある.この現象は捕捉効果として知られ,同一周波数を共用して利用する複数無線局間の離隔距離を決定する上でも重要である.本報告では,これらの無線信号がともにレイリーフェージングを受けることを仮定して,この捕捉効果を特性関数法を用いて解析する.
In general, receiving several radiowave signals interferes each other at a receiver. Under certain conditions, however, a signal having the largest magnitude controls the output at the demodulator in the receiver. The phenomenon is referred to as the capture effect. The report analyses the capture effect of two digital modulation signals having Rayleigh fading by means of the characteristic function method.

高橋 賢, “ISDB-T緊急警報放送における自動起動信号伝送路の非対称無記憶2元通信路近似,” 映像情報メディア学会誌, vol.72, no.1, pp.J47-J50, Jan. 2018. DOI: 10.3169/itej.72.J47.
Satoshi Takahashi, “Asymmetric memoryless binary channel approximation for automatic wake-up signal transmission channel in ISDB-T emergency warning broadcasting,” The Journal of The Institute of Image Information and Television Engineers, vol.72, no.1, pp.J47-J50, Jan. 2018. DOI: 10.3169/itej.72.J47.
URL: https://www.jstage.jst.go.jp/article/itej/72/1/72_J47/_article/-char/ja/

緊急時において,放送局が送信する特別な信号によりテレビ受信機を自動起動する方法はすでに実用化されている.しかしながら,特に移動テレビ受信機においては受信ビット誤りにより,この自動起動信号を見逃し,または誤検出することがある.一方で,災害の発生確率は極めて小さいので,受信機にて得られる相互情報量が,緊急警報にて得られる平均情報量と比較して著しく小さいならば,受信機に待機状態を維持させるよりも例えば休眠させる方が良いと考えられる.ここでは,放送局から受信機に至る自動起動信号の伝送路を非対称無記憶2元通信路に近似して,その信号受信により得られる相互情報量を求めることにより,情報理論的に自動起動信号の受信特性を解析する.
English abstract is available.

2017

高橋 賢, “[招待講演]ISDB-T緊急警報放送の自動起動信号判定方法,” 電子情報通信学会技術研究報告, RCS2017-258, Dec. 2017.
Satoshi Takahashi, “[Invited Talk] A method of determining automatic wake-up signal of ISDB-T emergency warning broadcasting,” IEICE Technical Report, RCS2017-258, Dec. 2017.
URL: http://www.ieice.org/ken/paper/20171214f1As/

ISDB-T(Integrated Services Digital Broadcasting-Terrestrial)地上ディジタルテレビ方式においては,緊急時において放送局が送信する特別な信号により,その受信機を自動的にオンにすることが可能である.本報告では,この自動起動信号が伝送されるTMCC(変調波伝送制御: Transmission and Multiplexing Configuration Control)信号に含まれるパリティを併用することにより,高信頼に自動起動信号を判定することを提案する.一方で,災害の発生確率は極めて小さい.このような自動起動受信機の適用領域を知るために,放送局から受信機に至る自動起動信号の伝送路を非対称無記憶2元通信路に近似して,その相互情報量を求める.
In ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) terrestrial digital television systems, it is possible to wake up television receivers with the special signal sent from the broadcaster when in emergency. In this report, a method of reliably determining the wake-up signal is proposed using the parity of TMCC (Transmission and Multiplexing Configuration Control), a control signal that is also used for the wake-up signal. Since a disaster would rarely occur, reception performance of the wake-up signal is analyzed calculating the mutual information to be obtained from a such wake-up receiver.

高橋 賢, “特性関数法を用いた複数ディジタル変調波に対する捕捉効果の解析,” 映像情報メディア学会冬季大会, 13C-3, Dec. 2017.
Satoshi Takahashi, “Analysis of capture effect with characteristic function method for digital modulated signals,” ITE Winter Annual Convention 2017, 13C-3, Dec. 2017.

異なるディジタル無線信号を同時に受信すると干渉が生じてビット誤りが増加する.所望信号が干渉信号よりも充分に強力であれば,干渉信号の影響をほとんど受けることなく通信可能であり,これは捕捉効果として知られる.この捕捉効果は干渉設計に重要であるが,これまでは実験的に評価されてきた.ここでは確率的に捕捉効果を解析する.
In general, receiving several radiowave signals interferes each other at a receiver. Under certain conditions, however, a signal having the largest magnitude controls the output at the demodulator in the receiver. The report analyses the capture effect of two digital modulation signals in terms of Rayleigh fading power fluctuation with the characteristic function method.

Koichi Tanaka, Hikaru Imatoku, Makoto Fujiwara, Naohisa Happo and Satoshi Takahashi, “A modeling of eigen-states in In0.53Ga0.47As/In0.52Al0.48As multi-quantum wells structure using photocurrent spectroscopy,” The 2017 International Symposium on Nonlinear Theory and Its Applications (NOLTA2017), pp.681–684, Cancun, Dec. 2017.

Determination of parameters is important for application to opto-electronic devices. We determined some band parameters in In0.53Ga0.47As/In0.52Al0.48As multi-quantum wells before. And experimental transition energies were obtained using photocurrent spectroscopy. Effective mass is estimated from the transition energies. E-k curve was drawn using a wave equation for our modeling studied by our experimental parameters.

Satoshi Takahashi, “Majority determination and subcarrier diversity of detecting broadcaster advised emergency wake-up signal for ISDB-T television receivers,” The 2017 International Symposium on Nonlinear Theory and Its Applications (NOLTA2017), pp.542–545, Cancun, Dec. 2017.

In an emergency, broadcaster would send a special signal to wake up their idle receivers. In ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) digital television, the emergency wake-up signal is sent on one of the control signals. As the control signal is sent over several subcarriers that contain the same information, the subcarrier diversity is possible for reliably determining the signal. Because ISDB-T broadcasting signal carries video contents not only for fixed receptions but also for mobile receptions, this paper focus on determining the wake-up signal for mobile receivers. In this paper, the performance of determining the wake-up signal with the subcarrier frequency diversity is presented. Then, the performance of determining the wake-up signal is presented by misdetections and false alarms.

高橋 賢, “ISDB-T緊急警報放送における自動起動信号伝送路の非対称無記憶2元通信路近似,” 映像情報メディア学会技術報告, BCT2017-76, Sept. 2017.
Satoshi Takahashi, “Asymmetric memoryless binary channel approximation for automatic wake-up signal transmission channel in ISDB-T emergency warning broadcasting,” ITEJ Technical Report, BCT2017-76, Sept. 2017.
URL: http://www.ite.or.jp/ken/paper/20170908lAgQ/

緊急時において,放送局が送信する特別な信号によりテレビ受信機を自動起動する方法はすでに実用化されている.しかしながら,特に移動テレビ受信機においては受信ビット誤りにより,この自動起動信号を見逃し,または誤検出することがある.一方で,災害の発生確率は極めて小さいので,このような信号を検出する受信機を常に待機状態にすべきかは議論すべき課題である.ここでは,放送局から受信機に至る自動起動信号の伝送路を非対称無記憶2元通信路に近似して,その信号受信により得られる相互情報量を求めることにより,情報理論的に自動起動信号の受信特性を解析する.
In emergency, the way of waking up television receivers by sending a special signal from the broadcaster has been realized. However, such mobile receivers would miss or wrongly detect the wake-up signal due to reception bit errors. On the other hand, it should be argued whether such receivers would continue waiting for the wake-up signal all the time or not, since a disaster would rarely occur. In this report, reception performance of the wake-up signal is analyzed calculating the mutual information to be obtained from a such wake-up receiver.

高橋 賢, “TMCCパリティを用いたISDB-T自動起動信号の低消費電力受信方法,” 映像情報メディア学会年次大会, 13C2, Aug. 2017.
Satoshi Takahashi, “A low-power reception method of ISDB-T emergency wake-up signal with TMCC parity,” ITE Annual Convention 2017, 13C2, Aug. 2017.

ISDB-T地上ディジタルテレビ方式においては,緊急時において放送局が送信する特別な信号により,その受信機を自動的にオンにすることが可能である.この自動起動信号が伝送されるTMCC制御信号に含まれるパリティを併用することでより高信頼に自動起動信号を判定することが提案されている.本論文では,この一致度合いにより自動起動信号状態の確からしさを判定することを提案し,さらにこの確からしさから消費電力を低減する受信方法を検討する.
This report proposes a method of reducing the power consumption of dedicated emergency wake-up receiver for ISDB-T broadcasting signals. Both the misdetection and false alarm probabilities increase as decreasing the reception power, then the receiver tends to wrong results. The proposal reduces the power consumption by determining these probabilities.

高橋 賢, “ISDB-T移動受信機におけるTMCCパリティ一致数に基づく自動起動信号受信の低消費電力受信方法,” 電子情報通信学会技術研究報告, CQ2017-59, Aug. 2017.
Satoshi Takahashi, “A low-power reception method of emergency wake-up signal based on TMCC parity agreement for ISDB-T mobile television receivers,” IEICE Technical Report, CQ2017-59, Aug. 2017.
URL: http://www.ieice.org/ken/paper/20170829Cbw4/

ISDB-T地上ディジタルテレビ方式においては,緊急時において放送局が送信する特別な信号により,その受信機を自動的にオンにすることが可能である.この自動起動信号が伝送されるTMCC制御信号に含まれるパリティを併用することでより高信頼に自動起動信号を判定することが提案されている.本論文では,このパリティを併用した方法において,受信したTMCC信号ビット列と自動起動信号の状態により決定されるビット列とを比較して,その一致数により自動起動信号状態の確からしさを判定することを提案する.さらにこの確からしさから消費電力を低減する受信方法を検討する.
In ISDB-T terrestrial digital television systems, it is possible to wake up television receivers with the special signal sent from the broadcaster when in emergency. A method of reliably determining the wake-up signal has been proposed using the parity of TMCC, a control signal and also used for the wake-up signal. This report proposes decreasing the receiver power consumption by determining the reliability of the wake-up signal. The reliability is obtained comparing the bit sequence of reception TMCC with the bit sequence associated with a condition of the wake-up signal.

高橋 賢, “緊急地震速報信号の受信装置及び受信方法,” 特開2017-011531, Jan. 12, 2017 (特許出願2015-125736, June 23, 2015).

2016

高橋 賢, “複数の制御信号サブキャリヤを周波数ダイバシチ合成するISDB-T移動テレビ受信機の緊急自動起動信号受信方法の比較,” 電子情報通信学会技術研究報告, CS2016-45, Nov. 2016.
Satoshi Takahashi, “Comparison among reception methods of emergency wake-up trigger for ISDB-T mobile television receiver with frequency diversity combining control signal subcarriers,” IEICE Technical Report, CS2016-45, Nov. 2016.
URL: http://www.ieice.org/ken/paper/20161111VbNc/

大規模災害が発生する可能性のあるとき,放送局はその送信電波に特別な信号を重畳することで受信機を強制的に自動起動させることができる.ISDB-T(Integrated Services Digital Broadcasting-Terrestrial)地上ディジタルテレビ方式は,この自動起動信号を制御信号によりディジタル形式のままに伝送する特徴があり,より確実にその信号を伝達することを目指している.ISDB-T放送信号は複数サブキャリヤにて伝送される.その制御信号情報もまた複数のサブキャリヤにわたり同一情報が約0.2秒ごとに巡回的に送信される.ISDB-Tでは,同一周波数帯域にて通常放送信号に加えて移動体向け放送信号を同時に伝送できるので,ビット誤りの多い移動受信においても自動起動信号を確実に受信できることは重要である.本論文では,自動起動信号をより確実に受信するために,制御信号のサブキャリヤ周波数ダイバシチが必要なことを示し,単一ビット検出,誤り訂正,およびパリティ多数決それぞれの方法を自動起動信号の見逃しと誤警報によりその性能を評価する.
In an emergency situation, broadcaster can wake up the receivers automatically by sending a special signal superposed on the transmission radiowave. ISDB-T terrestrial digital television transmits the emergency wake-up signal on one of the control signals, and it enables us to reliably convey the signal to the receivers. An ISDB-T broadcasting signal is sent by various subcarriers, and the control signal information is also sent by the several subcarriers that contain the same information and is repeated cyclically in every 0.2 second. Because ISDB-T conveys videos for not only fixed receptions but also mobile receptions, it is important for mobile receiver to reliably determine the emergency wake-up signal. In this paper, the requirement of the subcarrier frequency diversity is presented, Then, the performance of the single bit detection, the error correction detection, and the parity majority detection are compared in terms of misdetection and false alarm.

高橋 賢, “送信電力制御シュードライトの高所設置による遠近問題の軽減,” 電子情報通信学会技術研究報告, CS2016-46, Nov. 2016.
Satoshi Takahashi, “Reducing near-far problem by elevated pseudolite with transmission power control,” IEICE Technical Report, CS2016-46, Nov. 2016.
URL: http://www.ieice.org/ken/paper/20161111fbN2/

人工衛星を用いた地上測位では,その三次元測位のために最低4以上の衛星からの電波が届かなくてはならない.市街地のように天空が遮られる場所において,必要な衛星数を満たさない場所で測位を行えるようにするために,シュードライト(擬似衛星)が用いられることがある.地上に設置されるもので,人工衛星と同等のフォーマットの電波を送信して,一つの人工衛星と同じように振る舞う送信機である.このシュードライトからの電波が受信できる範囲では,その信号を必要な衛星の一つのものとして利用できる一方,その近くでは過大な電波強度のために人工衛星からの電波が受信できなくなる課題がある.この遠近問題の軽減のために,送信信号のパルス化とその電力制御が提案されている.本論文では,そのシュードライトを高所に設置することによるシュードライト信号の利用可能機会の増加と,遠近問題に起因する干渉増加とのトレードオフを評価する.
Three-dimensional satellite navigation on the ground requires radiowave reception from more than the four satellites. The use of a pseudo satellite, or pseudolite, would be a possible way for enabling us to know a users position. It is usually placed on the ground, transmits radiowave that is the same format as the navigation satellites transmit, and acts asthe navigation satellite. We can use a pseudolite as one of a needed satellite of obtaining the position within a distance the receiver can use the radiowave. In close vicinity to a pseudolite, however, the receiver encounters an excessive reception power and it results in lost of the position by blocking the satellite radiowaves. The phenomena is referred to as the near-far problem. For alleviating the effect, the burst pulse transmission and its power control have been proposed for the pseudolite radiowave. This paper evaluates increase in the availability of a pseudolite signal and reducing interference due to the near-far problem by elevating the pseudolite.

高橋 賢, “ISDB-T移動テレビ受信機におけるTMCC信号の受信方法,” 映像情報メディア学会年次大会, 12D1, Aug. 2016.
Satoshi Takahashi, “A reception method of TMCC signals for ISDB-T mobile television receivers,” ITE Annual Convention 2016, 12D1, Aug. 2016.

ISDB-Tの緊急警報放送の起動信号を移動受信するため,ワンセグ帯域内に含まれる4本のTMCCサブキャリヤを受信する低IF受信方法を提案する.使用するサブキ ャリヤ周波数の両端の中央をIFとして,サブキャリヤ周波数を要素とする行列の積和演算により一括復調する方法である.行列表現により複数サブキャリヤ信号表現の見通しが良くなり,周波数同期への適用も可能になった.
This report presents a method of receiving TMCC on ISDB-T broadcasting signals. TMCC signals contain the emergency wake-up trigger and the efficient reception would be useful for a prompt disaster alert. For decoding multiple TMCC subcarriers, the matrix representation of the low intermediate frequency receiver is proposed.

高橋 賢, “ISDB-T移動テレビ受信機のための制御信号受信方法,” 電子情報通信学会技術研究報告, CQ2016-52, Aug. 2016.
Satoshi Takahashi, “A method of receiving control signals for ISDB-T mobile television receivers,” IEICE Technical Report, CQ2016-52, Aug. 2016.
URL: http://www.ieice.org/ken/paper/20160829dbkb/

移動しながら利用するISDB-T(Integrated Services Digital Broadcasting-Terrestrial)地上ディジタルテレビ受信機において,緊急警報放送や緊急地震速報の自動起動信号を検出するための構成を検討した.これらの自動起動信号は,OFDM(Orthogonal Frequency Division Multiplexing)変調された放送信号の特定サブキャリヤにより伝達される.周波数選択性フェージングを伴う移動受信に起因するビット誤りを軽減するためには,同一内容が伝送されるそれら特定サブキャリヤ間での周波数ダイバシチが必要である.本報告において,離散的に配置された複数OFDMサブキャリヤ信号を受信するために,低中間周波数(low IF)構成のディジタル処理部分に着目して行列表現による復調処理することを提案する.
This report examines a method of receiving the automatic wake-up signals for detecting events of the Emergency Warning System (EWS) and the Earthquake Early Warning (EEW) on ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) signals. These wake-up signals are sent in specific subcarriers of OFDM (Orthogonal Frequency Division Multiplexing ) modulated broadcasting signals. For mobile television receivers where they encounter a higher bit error due to the frequency selective fading, the frequency diversity over the subcarriers that contain the same message is required. In this report, the digital signal processing in the digital low intermediate frequency (low IF) structure is considered and the demodulation method with the matrix representations over the subcarrier frequency components is proposed.

Satoshi Takahashi, “Detecting broadcaster transmitted earthquake early warning signal with AC parity for ISDB-T digital television receivers,” IEICE Information and Communication Technology Forum (IEICE ICTF 2016), pp.1-4, Patras, July 2016.
URL: https://www.ieice.org/publications/proceedings/summary.php?expandable=4&iconf=ICTF&session_num=A2&number=A2-4&year=2016

When significant disaster occurs, certain television broadcasters can wake up their receivers with a special signal. Such wake-up televisions are already available in the world. In ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) digital television in Japan, there are two wake up methods: Emer- gency Warning System (EWS) and Earthquake Early Warning (EEW). A wake-up indication of EWS comes from a single bit of the control channel and a method of efficiently detecting the wake up signal with parity variations is known. The EEW wake-up signal, however, contains detailed information messages in addition to the wake-up indication. This paper focuses on determining only the EWS wake-up indication and proposes a method of detecting the indication.

Satoshi Takahashi, “Detection of EEW wake-up signal with AC parity for ISDB-T television receivers,” IEICE Communication Express (ComEX), vol.5, no.7, pp.203-208, July 2016. DOI: 10.1587/comex.2016XBL0068.
URL: https://www.jstage.jst.go.jp/article/comex/5/7/5_2016XBL0068/_article

When local meteorological agencies advise an emergency alert, ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) television broadcasters would send a special signal to wake up the receivers. There are two ways of waking up: "Emergency Warning System (EWS)" that advises tsunami and earthquake disasters, and "Earthquake Early Warning (EEW)" that advises significant earthquake disasters. For detecting EWS wake-up indications, the use of the parity has been proposed. The method assumed the broadcasters do not change the message except for the wake-up indication. Because we cannot apply the method to an EEW wake-up indication detection, this letter proposes a method for EEW.

Satoshi Takahashi, “Detection of earthquake early warning on ISDB-T terrestrial digital television signals with majority decision,” IEICE Technical Report, SR2016-25 (SmartCom 2016), May 2016.
URL: http://www.ieice.org/ken/paper/20160517ubiq/

In emergency, an Integrated Services Digital Television-Terrestrial (ISDB-T) broadcaster would sent a special signal to wake up the receivers by a request of the meteorological agency. Both of the two wake-up ways, Emergency Warning System (EWS) and Earthquake Early Warning (EEW) in ISDB-T use the control channels. In this paper, we focus on determining EEW wake-up trigger with lower misdetection and false alarm probabilities. The EEW message contains both of the wake-up trigger and the detailed information, and this paper proposes a method of determining the trigger with the majority decision of the EEW parity and the simultaneous receptions of EEW and EWS signals.

高橋 賢, “緊急警報放送信号の同期バーストを活用したISDB-T緊急地震速報信号の検出方法,” 電子情報通信学会総合大会, B-8-59, March 2016.
Satoshi Takahashi, “A Method of detecting ISDB-T earthquake early warning signals with synchronization burst of emergency warning signals,” IEICE General Conference, B-8-59, March 2016.
URL: http://www.ieice.org/jpn/event/program/2016G/Settings/ab/b_08_059.html

ISDB-T地上ディジタルテレビ放送の制御信号に重畳される可能性のある緊急地震速報(EEW)の開始信号をより確実に検出する方法を提案する.TMCC信号とAC信号とでフレーム先頭が一致していることから,緊急警報放送(EWS)信号が伝送されるTMCC信号でフレーム同期を確保した上で,さらにEEW終了信号に特徴的なパリティとEEW信号が伝送されるときに確定される先頭3ビットによりその開始信号を多数決判定する方法である.同一の見逃し確率を得る条件において,提案法は従来法よりも誤警報確率を小さくすることができた.

2015

高橋 賢, “パリティ用いたISDB-T緊急地震速報信号の一検出方法,” 電子情報通信学会ソサイエティ大会, B-8-2, Sept. 2015.
Satoshi Takahashi, “A method of detecting ISDB-T earthquake early warning signals with parity,” IEICE Society Conference, B-8-2, Sept. 2015.
URL: http://www.ieice.org/jpn/event/program/2015S/Settings/ab/b_08_002.html

ISDB-T地上ディジタルテレビ受信機における緊急地震速報(EEW)信号の検出方法を提案する.テレビ放送局からの特別な信号により受信機を自動起動する課題において,より低い誤警報確率となるEEW信号検出方法が望まれる.本論文ではEEW信号の開始信号のみの待機受信に的を絞り,同期信号検出時において,終了信号以外をその開始信号とみなすことを提案する.誤警報確率の点でパリティをEEW信号検出に用いる効果を明らかにした.

高橋 賢, “ISDB-T地上ディジタルテレビにおいて緊急警報放送信号との同時受信を行う緊急地震速報信号の検出方法,” 電子情報通信学会技術研究報告, CS2015-39, Sept. 2015.
Satoshi Takahashi, “A method of detecting earthquake early warning signals for ISDB-T terrestrial television with emergency warning signal detection,” IEICE Technical Report, CS2015-39, Sept. 2015.
URL: http://www.ieice.org/ken/paper/201509031bcb/

地上ディジタルテレビ方式ISDB-Tの緊急時における受信機の自動起動方法には,緊急警報放送と緊急地震速報とがある.前者はTMCC信号と呼ばれる制御信号にて,後者はAC信号と呼ばれる制御信号にて伝達される.移動しながらこれらの緊急情報を待機受信する利用者に対して,緊急状態にあるかどうかを知ることは重要である.本論文において,緊急地震速報信号を検出するために,TMCC信号にてフレーム同期をとりながら,AC信号のパリティを用いることを提案する.
There are two ways of automatically waking up an ISDB-T television receiver. They are referred to as the emergency warning system and the earthquake early warning. The former uses a control channel named transmission and modulation configuration control, TMCC, and the latter employs an another control channel named the auxiliary channel, AC. It is important for mobile users receiving these signals to be initially advised whether an emergency alert is issued. A method of detecting the earthquake early warning signal with the AC parity while synchronizing the frame by means of TMCC is proposed in this paper.

Satoshi Takahashi, “Comparison of two majority determination methods of detecting emergency wake-up trigger for ISDB-T terrestrial digital television receivers,” The International Wireless Communications & Mobile Computing Conference (IWCMC 2015), pp.194-198, Dubrovnik, Aug. 2015. DOI: 10.1109/IWCMC.2015.7289081.
URL: http://ieeexplore.ieee.org/document/7289081/

ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) digital television receivers would wake up themselves when the broadcaster sends a special control signal. TMCC (Transmission and Modulation Configuration Control), one of the ISDB-T control signal, conveys the emergency wake-up trigger as well as the modulations and coding rates information. Even the TMCC also contains parity for the error correction, the receivers would cause misdetection or make false alarms the trigger in mobile and erroneous transmission channels. If we assume information of the modulations and the coding rates hold between before and after the emergency alert is advised, several bits of the parity is also used for the trigger detection because it reflect TMCC information. The majority detection with the parity bits reduces the false alarm. Because the parity can correct TMCC information bit by bit with a majority decoding, this paper compares performance of the two majority detection methods.

Satoshi Takahashi, “Detection of emergency wake-up trigger signal with TMCC parity and subcarrier frequency diversity for ISDB-T digital television receivers,” 10th Asia-Pacific Symposium on Information and Telecommunication Technologies (APSITT 2015), pp.1-3, Colombo, Aug. 2015. DOI: 10.1109/APSITT.2015.7217106.
URL: http://ieeexplore.ieee.org/document/7217106/

When emergency alert is advised, some digital television broadcasters would send a special control signal to wake up receivers. In ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) digital television standard, the special control signal is referred to as TMCC (Transmission and Modulation Configuration Control). It is capable of handling such emergency wake up and is also used for identifying the transmission parameters such as the modulations and coding rates. Because the transmission parameters are usually fixed, the use of the parity in the special control signal has been proposed for detecting emergency wake-up trigger. Though the parity method reduces the false alarm probability, it offers the same misdetection probability as the conventional wake-up trigger detection. Therefore, in this paper, the frequency diversity as well as the parity is used for further reducing the misdetection probability. The result showed the proposed combination of the parity detection and the frequency diversity complementary reduced probabilities both of the false alarm and the misdetection.

高橋 賢, “ISDB-T地上ディジタルテレビ受信機におけるACパリティを用いた緊急地震速報信号の検出,” 電子情報通信学会技術研究報告, CS2015-35, July 2015.
Satoshi Takahashi, “Detection of early earthquake warning signal with AC parity for ISDB-T terrestrial digital television receivers,” IEICE Technical Report, CS2015-35, July 2015.
URL: http://www.ieice.org/ken/paper/201507039bBe/

大規模災害発生時において,放送局からの特別な信号により強制的に受信機を自動起動させるアイディアはすでに実現されている.地上ディジタルテレビ方式ISDB-Tでは,そのような自動起動信号を制御信号により伝送する点に特徴があり,発生頻度の低い大規模災害への警報をより少ない消費電力にて待機受信できることを目標にしている.現在,日本での受信機自動起動方法には,「緊急警報放送(EWS: Emergency Warning System)」と呼ばれる地震や津波に対する警報の有無を制御信号にて伝送する方法と,「緊急地震速報(EEW: Earthquake Early Warning)」と呼ばれる地震の有無と詳細情報を異なる制御信号にて伝送する方法の2種類がある.このような自動起動信号をより小さな誤警報確率にて検出するため,緊急警報放送信号に対してそのパリティを併用することが提案されている.この方法は緊急状態の前後にて自動起動状態以外が変化しないことを前提にしているために,そのままでは緊急地震速報の検出には利用できない.本論文において,その制御信号パリティを用いた緊急地震速報信号の検出方法を提案する.
Methods of automatically waking up television receivers with the special signal sent from the broadcaster when a significant disaster occurs are already available. When local meteorological agencies advised an emergency alert, ISDB-T digital television broadcasters send such special signals in the control signal for detecting the signal. Sending such signals in the control channel reduces the power consumption of the receivers when they are idle, because significant disasters would rarely occur. There are two ways of the automatic wake-up. One is "Emergency Warning System (EWS)," that advises tsunami and earthquake disasters. Another is "Earthquake Early Warning (EEW)," that also advises the earthquake details. For detecting such automatic wake-up signals, the use of the parity has been proposed for EWS signal detection of receivers. Because the method assumes the broadcasters do not change the control signal contents except for the automatic wake-up information, and we need further changes for detecting EEW signals with the method. Therefore, this paper proposes the changes of the method for reliably detecting EEW signals.

高橋 賢, “セグメント内サブキャリヤダイバシチを用いたISDB-T緊急警報放送信号の検出,” 電子情報通信学会総合大会, B-8-29, March 2015.
Satoshi Takahashi, “Detection of ISDB-T emergency warning broadcasting signals with subcarrier diversity within an segment,” IEICE General Conference, B-8-29, March 2015.
URL: http://www.ieice.org/jpn/event/program/2015G/Settings/ab/b_08_029.html

ISDB-T地上ディジタルテレビにおいて緊急警報放送が行われると,TMCC情報にある自動起動フラグ(EWSフラグ)1ビットが設定される.著者は緊急警報放送信号を移動しながら待機受信するために,102ビットのTMCC情報うちEWSフラグ以外は変化しないことを仮定して,TMCCパリティを併用して検出することを提案した.ダイバシチの利用はその利得によりビット誤り率を低くできが,移動受信機においては軽減困難な誤りが生じてダイバシチ効果が得られない懸念がある.確率母関数法によりダイバシチ効果を求めて,提案法とダイバシチの併用により相補的に受信特性を改善できることを明らかにした.

高橋 賢, “ISDB-Tディジタルテレビにおける伝送モードの異なる緊急警報放送信号の検出方法,” 電子情報通信学会技術研究報告, CS2014-93, Feb. 2015.
Satoshi Takahashi, “A method of determining emergency warning signals with various transmission modes for ISDB-T digital terrestrial television receivers,” IEICE Technical Report, CS2014-93, Feb. 2015.
URL: http://www.ieice.org/ken/paper/20150226jBXB/

緊急警報放送とは地震発生や津波発生などの災害時においてテレビ放送局からの特別な信号により受信機を起動するもので,すでにいくつかの国々で実用化されている.ISDB-Tディジタルテレビ方式では緊急警報放送のための自動起動信号が制御信号上にあることに特徴があり,その自動起動信号を検出するいくつかの方法が提案されている.この制御信号は主に変調方式などの伝送モードを受信機に伝えるものである.制御信号のパリティを用いて自動起動信号を検出する方法は平時の伝送モードを仮定しているが,すべての放送局で常に同じ伝送モードが用いられるとは限らない.本論文では,初期状態においては制御信号のパリティを伝送モード検出の誤り訂正として用いる一方,緊急警報放送待機受信時においてはパリティを自動起動信号の検出のみに用いることを提案する.
Emergency warning broadcasting wakes up television receivers by a special control signal sent from the broadcaster when in emergency such as earthquake or tsunami disaster, and such emergency wake-up is already available in some countries. The wake-up signal of ISDB-T digital television broadcasting standard is on the control signal, and various methods have been proposed to detect the emergency wake-up trigger. The control signal has mainly used for advising the receivers of the transmission mode such as the modulation and the coding rate. A method of detecting the emergency warning broadcasting with the parity on the control signal has been proposed and it assumes the normal transmission mode. But all broadcasters would not use the assumed transmission mode. In this paper, a method of initially using the parity for correcting the transmission mode detection error and using the parity for detecting the emergency wake-up signal when in idle is proposed.

2014

高橋 賢, “緊急警報放送信号の受信装置及び受信方法,” 特開2014-225853, Dec. 4, 2014 (特許出願2013-117319, May 15, 2013).

高橋 賢, “[特別講演] ISDB-T地上デジタルテレビでの緊急警報放送信号の受信および放送方法,” 映像情報メディア学会技術報告, BCT2014-85, Nov. 2014.
Satoshi Takahashi, “[Special Talk] Methods of receiving and broadcasting emergency warning signals for ISDB-T terrestrial digital television standard,” ITEJ Technical Report, BCT2014-85, Nov. 2014.
URL: http://www.ite.or.jp/ken/paper/20141113vAeD/

ISDB-T地上デジタルテレビ方式は固定受信向け放送と移動受信向け放送を同一無線帯域にて伝送できる柔軟な伝送方法を備え,さらに緊急時にはテレビ受信機を起動してニュースチャネルに切り替える手段を有している.これらの機能は伝送制御信号(TMCC信号)に記述された情報により決定されるので,TMCC信号の受信方法と放送方法の工夫により緊急警報放送信号をより確実に検出できると考えられる.ここではTMCC情報のパリティに着目して,移動しながら緊急警報放送信号を待機受信する受信機の自動起動特性について検討したので報告する.
ISDB-T terrestrial digital television standard defines sending broadcasting signal for both fixed and mobile receptions simultaneously in the same radio bandwidth. In addition, the digital television broadcasters would wake up the receivers when in emergency and tune the emergency special program. The wake-up trigger is described in Transmission and Modulation Configuration Control (TMCC) signal, and the improvement in reliability of receiving emergency alert would be possible by ideas in reception and transmission methods of TMCC. In this paper, methods of emergency wake-up are proposed.

Satoshi Takahashi, “A novel method of determining EWS wake-up trigger for ISDB-T digital television receivers,” The 10th IEEE International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob 2014) Workshop on Emergency Networks for Public Protection and Disaster Relief (EN4PPDR 2014), pp.407-412, Larnaca, Oct. 2014. DOI: 10.1109/WiMOB.2014.6962193.
URL: http://ieeexplore.ieee.org/document/6962193/

ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) digital television broadcasters would send a special signal to wake up receivers when an emergency alert is advised. The wake-up procedure is defined as EWS (Emergency Warning System) and the trigger is sent in a single bit of the control message called TMCC (Transmission and Modulation Configuration Control). Wrong determination of the trigger leads to a false alarm and increases power consumption while idle. In this paper, a method of determining the EWS wake-up trigger is proposed by assuming the broadcasters do not change TMCC message except for the trigger when the broadcaster advises an emergency alert. For reducing the false alarm, this paper proposes using the TMCC parity for the reliable determination of the trigger. Results showed the proposed method was almost free from a false alarm.

Satoshi Takahashi, “Detection performance of emergency wake-up signal with frequency diversity for ISDB-T digital television receivers,” IEICE Technical Report, SR2014-86 (SmartCom 2014), Singapore, Oct. 2014.
URL: http://www.ieice.org/ken/paper/20141031NBSY/

Integrated Services Digital Television - Terrestrial (ISDB-T) broadcasters would send a special signal to wake up receivers when emergency alert is advised. The special signal is also used for identifying the transmission parameter, such as the modulations and coding rates, but it is usually fixed. Therefore, the use of the parity in the special signal is proposed for detecting emergency alert trigger. In this paper, the frequency diversity as well as the parity is used for further improving the detection performance. Result indicated the combination of the proposed detection with the parity and frequency diversity was almost free from false alarm even in the mobile reception at the velocity of 100 m/s.

高橋 賢, “32キロポイントFFTでのISDB-T緊急警報放送信号の検出特性,” 電子情報通信学会ソサイエティ大会, B-8-40, Sept. 2014.
Satoshi Takahashi, “Detection performance of ISDB-T emergency warning broadcasting signal with 32-kilo point FFT,” IEICE Society Conference, B-8-40, Sept. 2014.
URL: http://www.ieice.org/jpn/event/program/2014S/Settings/ab/b_08_040.html

日本におけるISDB-T地上ディジタルテレビ方式の放送信号は8キロポイントFFTでの5,612サブキャリヤにより伝送されるが,同一帯域幅にて大容量化するために,32キロポイントFFTでの22,465サブキャリヤ伝送が検討されている.また,緊急警報放送前後において,TMCC情報102ビットのうちEWSフラグ以外の変化がないことを仮定したときに,82ビットTMCCパリティの35ビットが変化することを示し,変化ビットの多数決にて緊急警報放送信号を検出することが提案されている.本論文は,この方法が32キロポイントFFTを用いる緊急警報放送信号の検出においても誤警報確率を削減できることを明らかにしている.

高橋 賢, “ISDB-Tディジタルテレビ放送の緊急警報におけるネクスト情報の活用,” 電子情報通信学会技術研究報告, CS2014-50, Sept. 2014.
Satoshi Takahashi, “Utilization of next information for emergency warning in ISDB-T terrestrial digital television broadcasting,” IEICE Technical Report, CS2014-50, Sept. 2014.
URL: http://www.ieice.org/ken/paper/20140912DBqv/

ISDB-T地上ディジタルテレビ放送局は,緊急時においてテレビを自動起動する特別な信号を送信することがある一方,その自動起動と同じ制御信号を用いて変調方式や符号化率などの伝送パラメータを柔軟に設定できる.伝送パラメータを変更する際には,事前に「ネクスト情報」として新たな伝送パラメータを通知することになっているが,その運用は放送事業者に任されている.本論文において,カレント情報と同一に固定化されたネクスト情報を緊急時においてはヌルに設定することにより,テレビ自動起動信号の検出特性を高められることを示す.
Integrated Services Digital Television - Terrestrial (ISDB-T) broadcasters would send a special signal to wake up receivers when emergency alert is adviced. On the other hand, the broadcasters can also use the special signal to change the transmission parameter, such as the modulations and coding rates, that it is usually fixed. Prior to change the transmission parameter, broadcasters would advice receivers the intension with the next information in the signal. However, the operation to use the information is up to broadcasters and most of all ISDB-T broadcasters use the next information as same as the current infomation. This paper shows the emergency wake-up performance could be improved by substituing the next information as null when emergency alert is adviced.

高橋 賢, “直線配置した送信電力制御シュードライトのカバレージ,” 電子情報通信学会総合大会, B-8-23, March 2014.
Satoshi Takahashi, “Coverage of transmission power controlled pseudolite with linear arrangement,” IEICE General Conference, B-8-23, March 2014.
URL: http://www.ieice.org/jpn/event/program/2014G/Settings/ab/b_08_023.html

GPS衛星が放送する電波と同等の電波を放送するシュードライト(PL)は測位に必要な衛星数を増やすことができる一方,PL近傍の受信機がGPS電波を遮断する遠近問題が課題になる.PL電波のパルス化は,その送信時間以外ではGPS電波に干渉しないので,時間平均した干渉を小さくできる.ここではPLを3台に増やし,直線状にPLを配置したときのカバレージと干渉のトレードオフを求める.その結果,パルス数2または3の送信電力制御PLはカバレージと干渉のよいトレードオフになることがわかった.

高橋 賢, “複数配置した送信電力制御シュードライトの干渉特性,” 電子情報通信学会技術研究報告, CS2013-129, March 2014.
Satoshi Takahashi, “Interference characteristics of multiple arrangement pseudolites with transmission power control,” IEICE Technical Report, CS2013-129, March 2014.
URL: http://www.ieice.org/ken/paper/20140307bBlb/

擬似衛星(シュードライト)はGPS衛星が放送する同一の周波数と同一のフォーマットを用いる地上送信機である.シュードライトは衛星測位の利用可能性を高めることができる一方,シュードライトには近傍にある受信機に過大な入力を与えて測位を不能にする遠近問題の課題がある.この遠近問題を軽減するために,送信電力をステップ状に低減する方法が提案されている.本論文では,天頂方向への見通しが遮られるような環境,例えば高架の下にある道路においてシュードライトを設置したときに,シュードライトがGPS衛星受信に与える干渉および複数シュードライトが互いに与える干渉をシミュレーションにより求める.本文中に例において,サービスエリア拡大のために追加したシュードライトは他のシュードライトに干渉を与えないことや,送信電力をステップ状に低減するシュードライトはカバレッジを高めることが明らかになった.
A pseudo satellite, or pseudolite, is a ground transmitter that broadcasts signals as the same frequency and the same format as the navigation satellites broadcasts. It enables us to augment the availableability of satellite navigation. However, a pseudolite would give an excessive power to the receiver close proximity to the pseudolite, and it result in block the GPS satellite signals reception. Therefore, a method of alleviating the near-far problem by reducing transmission power step-by-step has been proposed. In this paper, we focus on pseudolites operating in environments where the visibility for the zenith direction is blocked. Such environments often appear such in a road under an elevated road, and interference of pseudolite signals on GPS satellite signal reception and mutual interference of signals transmitted from the pseudolites are obtained from computer simulation. Results showed an additional pseudolite as an extension of the service area did not interfere the other pseudolites, and numerical result exhibited the pseudolite with step-by-step transmission power reduction increased the coverage in the service area.

高橋 賢, “市街地に複数配置した送信電力制御シュードライトのパルスデューティ比,” 電子情報通信学会技術研究報告, CS2013-86, Jan. 2014.
Satoshi Takahashi, “Pulse duty ratios of transmission power controlled pseudolites in a city area,” IEICE Technical Report, CS2013-86, Jan. 2014.
URL: http://www.ieice.org/ken/paper/20140122mBjM/

市街地においては高層建物によりGPSからの電波が遮蔽されることがある.シュードライトは衛星群が放送する電波と同様のフォーマットで電波を放送する地上送信機であり,このような場所でのGPSの利用可能性を高めることが期待できる.しかしながら,シュードライト近傍の受信機は,シュードライトからの電波がGPSからの電波を遮断する遠近問題が課題である.本論文ではシュードライト電波をパルス状にして,さらに電力制御を行ったときのパルスデューティ比と利用可能性のトレードオフを検討する.
A pseudolite, or in short, pseudolite is a ground transmitter that broadcasts signals as the same format as the navigation satellites broadcasts. It enables us to augment the availability of satellite navigation. However, a pseudolite has on an excessive power to the receiver, and it often blocks satellite signals. A method of alleviating the near-far problem by reducing transmission power step-by-step has been proposed. In this paper, the number of available pseudolites and the intereference. Results showed the method could make use of two pseudolite signals.

2013

高橋 賢, “異なるISDB-T伝送モード下でのTMCCパリティを用いた緊急警報放送信号の検出特性,” 映像情報メディア学会技術報告, BCT2013-109, Dec. 2013.
Satoshi Takahashi, “Detection performance of emergency warning broadcasting signals with TMCC parity in various ISDB-T transmission modes,” ITEJ Technical Report, BCT2013-109, Dec. 2013.
URL: http://www.ite.or.jp/ken/paper/20131206rAdY/

地震や津波が発生する恐れのあるとき,日本では地方自治体や気象庁などの要請により「緊急警報放送」が行われる.地上デジタルテレビ方式ISDB-Tでの緊急警報放送の検出方法として,TMCCパリティを用いる方法を検討した.ISDB-T方式は伝送モードを柔軟に設定できることから,緊急警報放送用起動フラグにより変化し,かつ伝送モードに依存しないTMCCパリティを求める.その結果,緊急警報用起動フラグの26ビットが1であること,パリティの124ビットが0であること,および187ビットが0であることの3ビットの状態から緊急状態を判断することができることを見いだした.同一の見逃し確率において,提案法は従来法よりも数桁の誤警報確率の低減が見込まれることがわかった.

高橋 賢, “複数配置したパルス電力制御シュードライトのカバレッジ,” 電子情報通信学会技術研究報告, CS2013-70, Dec. 2013.
Satoshi Takahashi, “Coverage of multiple arrangement pulse pseudolite with transmission power control,” IEICE Technical Report, CS2013-70, Dec. 2013.
URL: http://www.ieice.org/ken/paper/20131205kBIu/

シュードライトは,衛星測位において衛星群が送信する電波と同等の電波を送信する地上送信機であり,天空の一部が遮られる場所での測位利用可能性を高めるために用いられる.しかしシュードライト近傍ではその受信電力が過多になり衛星信号を遮断してしまう課題がある.そこで送信電力をステップ状に低減することにより遠近問題を軽減する方法が提案されている.本論文では複数のシュードライトが設置されたときに利用可能なシュードライト数や衛星受信に与える干渉を解析する.その結果,この方法により同時に複数のシュードライト信号が受信できることがわかった.
A pseudolite, or in short, pseudolite is a ground transmitter that broadcasts signals as the same format as the navigation satellites broadcasts. It enables us to augment the availability of satellite navigation. However, a pseudolite has on an excessive power to the receiver, and it often blocks satellite signals. A method of alleviating the near-far problem by reducing transmission power step-by-step has been proposed. In this paper, the number of available pseudolites and the intereference. Results showed the method could make use of two pseudolite signals.

高橋 賢, “移動受信環境におけるISDB-T緊急警報放送の信号検出特性,” 電子情報通信学会技術研究報告, CQ2013-66, Nov. 2013
Satoshi Takahashi, “Signal detection characteristics of ISDB-T emergency warning broadcasting in mobile reception environments,” IEICE Technical Report, CQ2013-66, Nov. 2013.
URL: http://www.ieice.org/ken/paper/20131115XBHl/

日本のテレビ放送では,地震・津波が発生したときや発生する恐れのあるときに「緊急警報放送」が行われることがある.ISDB-T方式に基づくディジタルテレビ の中には緊急警報放送が行われたときに,自らの電源をオンにして特定放送局の放送を受信する機能を持つものがある.この緊急状態の判定はTMCC(伝送情報制御)信号にある緊急警報用自動起動フラグの値により行われるが,移動受信環境においてはドップラ広がりによりTMCC信号の受信誤りが増加して,このフラグの判定を誤る課題がある.TMCCパリティを併用した判定方法を用いることにより受信誤りを軽減できることが知られていることから,本論文においてはこの方法を移動受信環境に適用したときの特性を明らかにする.
In Japan, the emergency warning broadcasting, alerting occurrence of earthquake or tsunami, is in operation on the digital television signals. Some televisions with the ISDB-T terrestrial television broadcasting standard have the functions of turning the power on and selecting a disaster report program while the television station broadcasts the program. The detection is based on the information at the emergency warning flag in TMCC (Transmission and Modulation Configuration Control) signal in digital television signals. In a mobile reception environment, an increase in TMCC signal reception errors due to the Doppler spread results in error in detecting the emergency flag on TMCC signal. In this paper, the characteristics of detecting the emergency warning status with use of the TMCC parities as well as the emergency flag is evaluated in mobile reception environments.

高橋 賢, “パリティを用いたISDB-T緊急警報放送信号の検出方法,” 電子情報通信学会ソサイエティ大会, B-8-11, Sept. 2013.
Satoshi Takahashi, “A method of detecting ISDB-T emergency warning signal with parity bits,” IEICE Society Conference, B-8-11, Sept. 2013.
URL: http://www.ieice.org/jpn/event/program/2013S/Settings/ab/b_08_011.html

高橋 賢, “サブキャリヤ受信によるISDB-T地上ディジタルテレビ方式での緊急警報検出,” 電子情報通信学会技術研究報告, CS2013-27, July 2013.
Satoshi Takahashi, “A method of detecting emergency warning of ISDB-T terrestrial digital television standard with subcarrier reception,” IEICE Technical Report, CS2013-27, July 2013.
URL: http://www.ieice.org/ken/paper/20130705OB4g/

日本のテレビ放送やラジオ放送では,地震・津波が発生したときや発生する恐れのあるときに,地方自治体や気象庁などの要請により「緊急警報放送」が行われることがある.ISDB-T方式に基づくディジタルテレビの中には緊急警報放送が行われたときに,自らの電源をオンにして特定放送局の放送を受信するものがある.このような自動起動の根本的原理は,受信機が電源オフのときにも放送局信号を受信し続けることにある.ここではISDB-TのTMCC(伝送情報制御)信号のみを受信して,信号強度が低いときにおいても,緊急警報放送が行われているかどうかを判定する方法を提案する.
Television broadcasting stations in Japan will send emergency warning signal in case of possibility of significant earthquakes and tsunami. The signal will be sent by a request of local government or the Meteorological Agency. The digital television receivers, on the other hand, are capable of turning on the power and tuning the emergency program themselves when they receive the emergency warning signal specified by the standard of ISDB-T (Integrated Services Digital Broadcasting-Terrestrial). The essence of the self power-on mechanism is that the television or the radio listens to a specific broadcasting station even when the main power switch is off. In this paper, a method of detecting the emergency warning signal embedded in TMCC (Transmission and Modulation Configuration Control) of ISDB-T standard broadcasting signal is proposed.

高橋 賢, “ISDB-T地上ディジタルテレビ方式における緊急警報放送信号の検出方法,” 電子情報通信学会技術研究報告, SR2013-17, May 2013.
Satoshi Takahashi, “A method of detecting emergency warning signal in ISDB-T terrestrial digital television standard,” IEICE Technical Report, SR2013-17, May 2013.
URL: http://www.ieice.org/ken/paper/20130524IBdU/

日本のテレビ放送やラジオ放送では,地震・津波が発生したときや発生する恐れのあるときに,地方自治体や気象庁などの要請により「緊急警報放送」が行われることがある.また,テレビやラジオには,緊急警報放送が行われたときに,自らの電源をオンにして特定放送局の放送を受信する機能を持つものがある.このような自動起動の根本的原理は,受信機が電源オフのときにも特定放送局の信号を受信し続けることにある.特に,ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) 地上ディジタルテレビ方式ではディジタルの制御情報にてその状態が示される点において,「見なし音声」にてディジタル情報が伝送される他の放送方式と比較して,より小さな消費電力で自動起動が実現できる見込みがある.ここではISDB-T方式におけるTMCC(Transmission and Modulation Configuration Control)の緊急警報ビットの判定に加えて,TMCCのパリティビットも緊急警報放送の判定に用いることを提案する.
Television and radio broadcasting stations in Japan would send emergency warning signal in case of possibility of significant earthquakes and tsunami by a request of local government or the Meteorological Agency. Some televisions and radios are capable of turning on the power and tuning the emergency program themselves when the emergency warning broadcasting. The essence of the self power-on mechanism is that the television or the radio listens to a specific broadcasting station even when the main power switch is off. Especially, According to ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) digital television broadcasting specification standard, emergency warning signal is sent in a digital format. Therefore, comparing it with a television with the other standard, the power consumption of the detection circuit for ISDB-T emergency warning signal could be reduced because of the ISDB-T emergency warning is embedded and indicated in the digital control information. For detecting emergency warning, this paper proposes using parity bits, in addition to the emergency warning bit, in the digital control information.

高橋 賢, “送信電力制御を行う市街地シュードライトの干渉特性,” 電子情報通信学会総合大会, B-2-64, March 2013.
Satoshi Takahashi, “Interference characteristics of terrestrial pseudolite with transmission power control,” IEICE General Conference, B-2-64, March 2013.

高橋 賢, “送信電力制御を行う市街地シュードライトのパルスデューティ比,” 電子情報通信学会技術研究報告, CS2012-132, March 2013.
Satoshi Takahashi, “Pulse duty ratio of city area pseudolite with transmission power control,” IEICE Technical Report, CS2012-132, March 2013.
URL: http://www.ieice.org/ken/paper/20130315jBCz/

シュードライト(擬似衛星)は,衛星測位において衛星群が送信する電波と同等の電波を送信する地上送信機であり,天空の一部が遮られるような場合でも測位システムの利用可能性を高めることができる.しかし,シュードライト実現のためには,遠近問題として知られる,その近傍にて受信電力が過多になる干渉を軽減しなければならない.この遠近問題を軽減するため,送信電力をステップ状に低減する市街地シュードライトが提案されている.送信電力をステップ状に低減すると,シュードライト電波の第1パルスにより衛星信号が遮断された受信機が第2パルスまたは第3パルスを利用できる可能性があり,サービスエリア内において利用可能性が高まる.しかしながら,この方法はシュードライトがより長い時間にわたり電波を放送するため,干渉量が増加する懸念がある.そこで本論文ではこのシュードライトが受信機に与える干渉電力を評価して,干渉量の時間平均が所望の値になるシュードライトのパルスデューティ比を求める.その結果,送信電力をステップ状に低減するシュードライトは,干渉量の時間平均が同一である従来のシュードライトと比較して,カバレッジ確率を約1.5倍にできることがわかった.
A pseudo satellite, or pseudolite, is a ground transmitter that broadcasts signals in the same format as the satellites group broadcasts for satellite navigation. It enables us to augment availability of the satellite navigation even in block the sky visibility. For deployment of a pseudolite, we need to be solved the interference problem the receiver encounters excessive reception power at the close proximity to the pseudolite and it is referred to as the near-far problem. A city area pseudolite with step-by-step transmission power reduction has been proposed to mitigate the near-far problem. The receiver where the pseudolite blocks the satellite signal with the first pulse would have a chance to make use of the second or third pulse. It results in an increase in the availability. Because the method increases the transmission duration for a pseudolite, it would also increase the interference. In this paper, the interference power at the receiver is evaluated and calculates the pulse duty ratio of the pseudolite where the time-average interference power is a desired value. Comparing it with the conventional pseudolite, the pseudolite with step-by-step transmission power reduction increased the coverage probability by 1.5 times.

2012

Satoshi Takahashi, “Transmission power control of terrestrial pseudo satellite signal for global navigation satellite systems,” IEEE TENCON 2012, Cebu, Nov. 2012. DOI: 10.1109/TENCON.2012.6412250.
URL: http://ieeexplore.ieee.org/document/6412250/

In global navigation satellite systems (GNSS) such as Global Positioning System (GPS), we need signals from more than four satellites to find out the current three-dimensional location. However, the satellite visibility is occasionally blocked in city areas and the availability is decreased. In these areas, the ground placement of the pseudo satellite, or in short, pseudolite, has been proposed to augments the availability. It broadcasts the signal in the same format as the satellites broadcast, but it is known the signals from the satellites sometimes block by the pseudolite signal then, and the phenomenon is referred to as the near-far problem. Therefore, burst pulse-like transmission has been used for mitigating the average interference in the close proximity to the pseudolite, but the satellite signals remain unavailable to the users. In this paper, the coverage probability and the outage probability are analytically obtained where the receiver faces shadowing. Then a pseudolite with step-by- step transmission power reduction is proposed to enlarge the service area. Result showed the pseudolite with step-by-step power reduction outperformed the conventional burst pulse-like transmission pseudolite in terms of the coverage probability and the outage probability.

高橋 賢, “送信電力をステップ状に低減する市街地シュードライト,” 電子情報通信学会ソサイエティ大会, B-2-28, Sept. 2012.
Satoshi Takahashi, “A terrestrial pseudolite with step-by-step transmission power reduction,” IEICE Society Conference, B-2-28, Sept. 2012.

高橋 賢, “全地球衛星測位システムを補完するパルス電力制御シュードライトの特性評価,” 電子情報通信学会技術研究報告, CS2012-42, July 2012.
Satoshi Takahashi, “Performance evaluation of pulse power-controlled pseudolite for global navigation satellite system,” IEICE Technical Report, CS2012-42, July 2012.
URL: http://www.ieice.org/ken/paper/20120713m0TO/

GPSのような全地球衛星測位システム(GNSS)では,3次元での位置位置を知るために4衛星以上からの電波を同時に受信できなければならない.しかしながら,市街地ではしばしばこの視界が遮へいされる.このような場所において擬似衛星(pseudo satellite),略してシュードライト(pseudolite)を地上に設置することが提案されている.このシュードライトは衛星が放送する電波と同等の電波を放送するもので,そのことにより利用可能性が向上する.しかしながら,このときに衛星からの電波がシュードライト電波により遮断される遠近問題が生じることが知られている.そこでシュードライト近傍での干渉を軽減するためにパルス状に電波を送信することが提案されている.本論文では,受信機がシャドウイングを受けるときのカバレッジと不稼働率を解析的に求める.また,送信電力をステップ状に低減するシュードライトのカバレッジと不稼働率もまた計算する.その結果,送信電力をステップ状に低減するシュードライトはパルス状に電波を送信するシュードライトよりもよい特性を示すことがわかった.
In global navigation satellite systems (GNSS) such as Global Positioning System (GPS), we need signals from more than four satellites to find out the current three-dimensional location. However, the visibility is occasionally blocked in city areas. In these areas, the ground placement of the pseudo satellite, or in short, pseudolite, has been proposed. It broadcasts the signal in the same format as the satellites broadcast and augments the availability. However, it is known the signals from the satellites sometimes block by the pseudolite signal then, and it referred to as the near-far problem. Therefore, pulse-like transmission of has been used for mitigating the interference vicinity close to the pseudolite. In this paper, the coverage and the outage probability are analytically obtained where the receiver encounters shadowing. The coverage and the outage probability of a pseudolite that reduces the transmission power step-by-step are also calculated. Result showed the step-by-step power reduction pseudolite outperforms the conventional pulse-like transmission pseudolite.

高橋 賢, “全地球衛星測位システムにおける地上擬似衛星信号の送信方法,” 電子情報通信学会技術研究報告, CS2011-139, March 2012.
Satoshi Takahashi, “A method of transmitting terrestrial pseudo satellite signal in global satellite navigation system,” IEICE Technical Report, CS2011-147, July 2012.
URL: http://www.ieice.org/ken/paper/20120309Z0p2/

GPSに代表される全地球衛星測位システムにおいて,三次元での現在位置を知るためには異なる4以上の衛星からの電波を受信できなければならない.しかし,市街地においては建物などにより地平線方向への視界が遮蔽され,測位ができなくなることがある.そのような場所おいても測位を可能にするため,衛星と同等の信号を送信する擬似衛星(シュードライト)を地上に設置して,測位に必要な衛星を補間することが提案されているが,遠近問題が課題になる.そのようなときに,シュードライト電波をパルス状にすればこのシュードライト近傍での干渉を軽減できることが知られている.本論文では電力制御を行いながら連続してパルス状のシュードライト電波を送信することにより,サービスエリアを拡大することを提案する.
In global navigation satellite systems (GNSS) such as Global Positioning System (GPS), we need signals from more than four satellites to determine the current three dimensional location. However, the determination sometimes fails due to obstructions of the visibility of the horizontal direction. For augmentation of these satellite signals, the ground deployment of the pseudo satellite, or in short, pseudolite, has been proposed. But the near-far problem arises then. Pulse-like tranmission of has been used for mitigating the interference vicinity close to the pseudolite. In this paper, successive pulses transmission at the pseudolite with the power control is proposed to enlarge the service area.

2011

高橋 賢, “ホワイトスペースを活用して行う地上ディジタルテレビの緊急警報放送,” 第557回 日本学術会議電波科学研究連絡委員会 F分科会資料(URSI-F分科会), Sept. 2011.
Satoshi Takahashi, “Emergency warning broadcasting on terrestrial digital television system using spectral white spaces,” The 557th URSI-F Document in Japan, Sept. 2011.

高橋 賢, “ホワイトスペースを用いるディジタルテレビ放送局による地域緊急警報放送,” 電子情報通信学会技術研究報告, RCS2011-4, Apr. 2011.
Satoshi Takahashi, “A method of broadcasting local emergency warning by using a small terrestrial digital television transmitter with spectral white spaces,” IEICE Technical Report, RCS2011-4, Apr. 2011.

金丸 廣大, 筒井 健太, 高橋 賢, “地上テレビジョン放送波における潜在電界の3次元解析,” 電子情報通信学会技術研究報告, RCS2011-2, Apr. 2011.
Koudai Kanamaru, Kenta Tsutsui, and Satoshi Takahashi, “Three dimensional analysis of hidden signal strength for terrestrial television broadcasting radiowaves,” IEICE Technical Report, RCS2011-2, Apr. 2011.

筒井 健太, 金丸 廣大, 高橋 賢, “3次元空間における波到来方向測定系の構築,” 電子情報通信学会技術研究報告, RCS2011-1, Apr. 2011.
Kenta Tsutsui, Koudai Kanamaru, and Satoshi Takahashi, “A novel method of measuring radiowave direction of arrival in three dimensional space,” IEICE Technical Report, RCS2011-1, Apr. 2011.

Satoshi Takahashi, Hiroshi Harada, and Chang-Jun Ahn " Receiver, receiving method, program and information recording medium," United States Patent, 7,903,717, Jan. 28, 2011.

2010

Satoshi Takahashi, “A method of cognizing primary and secondary radio signals,” IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, vol.E93-A, no.12, pp.2682-2690, Dec. 2010. DOI: 10.1587/transfun.E93.A.2682.
URL: http://search.ieice.org/bin/summary.php?id=e93-a_12_2682&category=A&lang=E&year=2010&abst=

高橋 賢, “エネルギ検出に基づくコグニティブ無線における信号検出性能の変調方式依存性,” 電子情報通信学会技術研究報告, CS2010-46, Nov. 2010.
Satoshi Takahashi, “Modulation dependence on detection performance for cognitive radios based on energy detection,” IEICE Technical Report, CS2010-46, Nov. 2010.

高橋 賢, “地上テレビジョン放送帯域においてホワイトスペースを活用する無線通信,” 電子情報通信学会技術研究報告, RCS2010-102, Aug. 2010.
Satoshi Takahashi, “Radio communications utilizing spectral white spaces in terrestrial television broadcasting bands,” IEICE Technical Report, RCS2010-102, Aug. 2010.

Satoshi Takahashi, “A CFAR circuit with multiple detection cells for automotive UWB radars,” IEICE Transactions on Communications, vol.E93-B, no.6, pp.1574-1582, June 2010. DOI: 10.1587/transcom.E93.B.1574.
URL: http://search.ieice.org/bin/summary.php?id=e93-b_6_1574&category=B&lang=E&year=2010&abst=

高橋 賢, “差分帯域幅法を用いたコグニティブ無線における信号検出特性のスナップショット数依存性,” 電子情報通信学会総合大会, B-17-10, March 2010.
Satoshi Takahashi, “Dependence of the snapshot number on signal detection performance of a cognitive radios with the differentiated bandwidth method,” IEICE General Conference, B-17-10, Sept. 2010.

Satoshi Takahashi, “Signal detection performance of a cognitive radio with the differentiated bandwidth method,” IEICE Technical Report, CS2009-111, March 2010.

鈴木 俊郎, 武井 健, 高橋 賢, 宇佐美 浩志, 石田 雄爾, 丹治 彰, “無線通信方法,” 特許第4417324号, Feb. 17, 2010.

2009

Satoshi Takahashi, “A differentiated bandwidth technique for signal detection of cognitive radios and its analytical evaluation with the characteristic function method,” 12th Symposium on Wireless Personal Multimedia Communications (WPMC’09), S10-2, Sendai, Sept. 2009.

高橋 賢, “複数電力センサによるコグニティブ無線の差分帯域幅信号検出法,” 電子情報通信学会ソサイエティ大会, B-17-3, Sept. 2009.
Satoshi Takahashi, “A differentiated signal detection method for cognitive radios with multiple power sensors,” IEICE Society Conference, B-17-3, Sept. 2009.

高橋 賢, 原田 博司, 安 昌俊, “受信装置、受信方法、プログラム、および、情報記録媒体,” 特許4374478, Sept. 18, 2009.

Satoshi Takahashi, “A differentiated bandwidth technique for signal detection of cognitive radios and its analytical evaluation with the characteristic function method,” IEICE Technical Report, RCS2009-15, May 2009.

檜垣祥太, 高橋 賢, “既存のディジタルテレビジョン放送帯域を再利用して行う地域放送の干渉解析,” 電子情報通信学会技術研究報告, RCS2009-16, May 2009.
Shota Higaki and Satoshi Takahashi, “Interference analysis for regional broadcasting in existing digital television bands,” IEICE TEchnical Report, RCS2009-16, May 2009.

高橋 賢, “異なる帯域幅を使用するOFDMコグニティブ無線の信号検出法,” 電子情報通信学会総合大会, B-17-16, March 2009.
Satoshi Takahashi, “A signal detection method for cognitive radios with differentiated bandwidth,” IEICE General Conference, B-17-16, March 2009.

Satoshi Takahashi, “A CFAR circuit of detecting spatially correlated target for automotive UWB radars,” IEICE Technical Report, CS2008-62, Jan. 2009.

2008

Maiko Nakano, Hiroki Oda, and Satoshi Takahashi, “An activation management method for cognitive radios based on human activities,” 2008 International Symposium on Antennas and Propagation (ISAP), pp.983-985, Taipei, Oct. 2008.

Satoshi Takahashi, “A CFAR circuit of detecting spatially correlated target for automotive UWB radars,” 2008 International Symposium on Antennas and Propagation (ISAP), pp.1096-1099, Taipei, Oct. 2008.

Hiroshi Harada, Chang-Jun Ahn, Satoshi Takahashi, Yukiyoshi Kamio, Seiichi Sampei, “Communicating system, communicating method, base station, and mobile station,” United States Patent, 7,436,809, Oct. 14, 2008.

高橋 賢, “空間相関のある目標を検出する車載UWBレーダーのためのCFAR,” 電子情報通信学会ソサイエティ大会, B-2-15, Sept. 2008.
Satoshi Takahashi, “A constant false alarm rate circuit of detecting spatially correlated target for automotive UWB radars,” IEICE Society Conference, B-2-15, Sept. 2008.

Chang-Jun Ahn, Satoshi Takahashi, Hisato Fujisaka, Takeshi Kamio, and Kazuhisa Haeiwa, “Power consumption for coherent optical orthogonal frequency division multiplexing with punctured LDPC codes and variable amplitude block codes,” IEEE/OSA Journal of Lightwave technology, vol.26, no.14, pp.2227-2234, July 2008. DOI: 10.1109/JLT.2008.920138.
URL: http://ieeexplore.ieee.org/document/4609978/

Satoshi Takahashi and Chang-Jun Ahn, “An improvement factor of clutter suppression with statistical power correction for high resolution UWB radars,” IEICE Technical Report, CS2007-57, Jan. 2008.

2007

Satoshi Takahashi and Chang-Jun Ahn, “A statistical clutter suppression method based on given target-existence probabilities for high resolution UWB radars,” 2007 Wireless Personal Wireless Communications (WPMC), pp.860-863, Jaipur, Dec. 2007.

赤坂 謙一, 高橋 賢, 石田 賢治, “ユーザ体感品質の向上を目指した音響データの劣化に対する事前提示法,” 電子情報通信学会論文誌(B), vol.J90-B, no.10, pp.1059-1063, Oct. 2007.
Kenichi Akasaka, Satoshi Takahashi, and Kenji Ishida, “An alaram for sound quality degradation on unstable communication channels,” IEICE Transaction on Communication (Japanese Ed.), vol.vol.J90-B, no.10, pp.1059-1063, Oct. 2007.
URL: http://search.ieice.org/bin/summary.php?id=j90-b_10_1059&category=B&lang=J&year=2007&abst=

Chang-Jun Ahn, Satoshi Takahashi, and Kazuhisa Haeiwa, “Time-frequency interferometry for OFDM,” 2007 IEEE Asia-Pacific Conference on Communications (APCC), pp.153-156, Bangkok, Oct. 2007.

Satoshi Takahashi, Chang-Jun Ahn, and Kenji Ishida, “A battery saving method based on coordinate and individual sleeps for ad-hoc terminals,” 2007 IEEE Asia-Pacific Conference on Communications (APCC), pp.159-162, Bangkok, Oct. 2007.

Chang-Jun Ahn, Satoshi Takahashi, Takeshi Kamio, Hisato Fujisaka, and Kazuhisa Haeiwa, “Power consumption for coherent optical orthogonal frequency division multiplexing with punctured convolutional codes and variable amplitude block codes,” 2007 IEEE Asia-Pacific Conference on Communications (APCC), pp.465-468, Bangkok, Oct. 2007.

Chang-Jun Ahn, Satoshi Takahashi, and Kazuhisa Haeiwa, “Time-frequency interferometry for OFDM,” IEICE Technical Report, WBS2007-32, Oct. 2007.

Chang-Jun Ahn, Satoshi Takahashi, Takeshi Kamio, Hisato Fujisaka, and Kazuhisa Haeiwa, “Power consumption for coherent optical orthogonal frequency division multiplexing with punctured convolutional codes and variable amplitude block codes,” IEICE Technical Report, WBS2007-33, Oct. 2007.

Satoshi Takahashi and Chang-Jun Ahn, “A statistical clutter suppression method based on given target-existence probabilities for high resolution UWB radars,” IEICE Technical Report, WBS2007-37, Oct. 2007.

原田 博司, 安 昌俊, 高橋 賢, 神尾 享秀, 三瓶 政一, “通信システム、通信方法、基地局、および移動局,” 特許第4022625号, Oct. 12, 2007.

Chang-Jun Ahn, Satoshi Takahashi, and Kazuhisa Haeiwa, “Time-frequency interferometry for OFDM,” IEICE Society Conference, B-8-21, Sept. 2007.

赤坂 謙一, 高橋 賢, 石田 賢治, 松原 行宏, “ユーザ体感品質の向上を目指した音響データの劣化に対する事前提示法,” 電子情報通信学会ソサイエティ大会, B-11-11, Sept. 2007.
Kenichi Akasaka, Satoshi Takahashi, Kenji Ishida, and Yukihiro Matsubara, “An alarm for sound quality degradation on unstable communication channels,” IEICE Society Conference, B-11-11, Sept. 2007.

Satoshi Takahashi, Chang-Jun Ahn, and Kenji Ishida, “A battery saving method with two sleep modes for ad-hoc radio terminals operating in shadowing environments,” IEICE Society Conference, B-21-17, Sept. 2007.

Satoshi Takahashi, Chang-Jun Ahn, and Kenji Ishida, “A battery saving method of reducing energy consumption of ad-hoc radio terminals in shadowing environments,” IEICE Technical Report, IN2007-18, June 2007.

Chang-Jun Ahn, Makoto Taromaru, and Satoshi Takahashi, “Link correlation based transmit sector antenna selection for STBC/OFDM,” IEEE Wireless Communications and Networks Conference (WCNC 2007), Hong Kong, March 2007.

Chang-Jun Ahn, Satoshi Takahashi, and Makoto Taromaru, “High time resolution carrier interferometry for SDM/OFDM,” IEICE General Conference, B-5-89, March 2007.

Chang-Jun Ahn, Satoshi Takahashi, and Makoto Taromaru, “High time resolution carrier interferometry for SDM/OFDM,” IEICE Technical Report, RCS2006-227, Jan. 2007.

Chang-Jun Ahn, Satoshi Takahashi, and Makoto Taromaru, “Transmit sector selection with considering the link correlation for SDM/OFDM systems,” IEICE Technical Report, RCS2006-231, Jan. 2007.

2006

Chang-Jun Ahn, Satoshi Takahashi, and Makoto Taromaru, “Transmit sector selection with considering the link correlation for SDM/OFDM systems,” Innovations in Information Technology (IIT 2006), pp.1-5, Dubai, Nov. 2006.

Satoshi Takahashi, Takehiko Kobayashi, Chang-Jun Ahn, Kenji Ishida, “Effects of partial blocking of transmission array antenna on transmission performance of MIMO eigenbeam space-division multiplexing,” The First International Conference on Communications and Electronics (HUT-ICCE 2006), pp.184-187, Hanoi, Oct. 2006.

高橋 賢, 小林 岳彦, 安 昌俊, 石田 賢治, “MIMO固有ビーム伝送における送信アンテナ遮蔽の効果,” 電子情報通信学会ソサイエティ大会, B-1-214, Sept. 2006.
Satoshi Takahashi, Takehiko Kobayashi, Chang-Jun Ahn, and Kenji Ishida, “An effect of transmission antenna obstruction for MIMO eigenbeam space division multiplexing,” IEICE Society Conference, B-1-214, Sept. 2006.

Chang-Jun Ahn, Makoto Taromaru, and Satoshi Takahashi, “Link correlation based transmit sector antenna selection for STBC/OFDM,” IEICE Society Conference, B-8-8, Sept. 2006.

Satoshi Takahashi, Chang-Jun Ahn, Kenji Ishida, “An icosahedron antennas configuration for SVD-MIMO transmission,” The 3rd IEEE VTS Asia Pacific Wireless Communications Symposium (APWCS 2006), pp.324-327, Daejeon, Aug. 2006.

Chang-Jun Ahn and Satoshi Takahashi, “Performance evaluation of an OFDM using unitary matrix frequency modulation for power line communications over impulsive noise channels,” World Scientific and Engineering Academy and Society (WSEAS) Transactions on Communications, vol.5, no.3, pp.454-459, March, 2006.
URL: http://wseas.org/cms.action?id=4021

高橋 賢, 石田 賢治, “シャドウイング環境下でのアドホックネットワークの持続時間,” 電子情報通信学会総合大会, B-21-36, March 2006.
Satoshi Takahashi and Kenji Ishida, “Connection holding times of ad hoc networks in shadowing environments,” IEICE General Conference, B-21-36, March 2006.

Chang-Jun Ahn, Satoshi Takahashi, and Hiroshi Harada, “Unitary matrix frequency modulated OFDM for power line communications over impulsive noise channels,” International Conference on Electronic Hardware, Wireless and Optical Communications (EHAC2006), pp.45-49, Madrid, Spain, Feb., 2006.

Satoshi Takahashi, Chang-Jun Ahn, and Hiroshi Harada, “Stochastic method of determining substream modulation levels for MIMO eigenbeam space division multiplexing,” IEICE Transactions on Communications, vol.E89-B, no.1, pp.142-149, Jan. 2006. DOI: 10.1093/ietcom/e89-b.1.142.
URL: http://search.ieice.org/bin/summary.php?id=e89-b_1_142&category=B&lang=E&year=2006&abst=

2005

高橋 賢, 石田 賢治, “シャドウイング環境下でのアドホックネットワーク接続可能性,” 電子情報通信学会技術研究報告, IN2005-121, Dec. 2005.
Satoshi Takahashi and Kenji Ishida, “Connection availability over ad-hoc networks in shadowing environments,” IEICE Technical Report, IN2005-121, Dec. 2005, in Japanese.

Chang-Jun Ahn, Satoshi Takahashi, and Hiroshi Harada, “Throughput enhancement with differentially modulated pilot symbol assisted subcarrier block modulation using uplink delay spread for adaptive downlink OFDM,” International Symposium on Wireless Personal Multimedia Communications (WPMC'05), vol.2, pp.877-881, Aalborg, Sept. 2005.

Chang-Jun Ahn, Satoshi Takahashi, and Hiroshi Harada, “Adaptive subcarrier block modulation with differentially modulated pilot symbol assistance for downlink OFDM using uplink delay spread,” 2005 IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), no.E6-2, Berlin, Sept. 2005.

高橋 賢, “MIMO固有ビーム伝送における正20面体アンテナ配置,” 電子情報通信学会ソサイエティ大会, B-1-219, Sept. 2005.
Satoshi Takahashi, “An icosahedron antennas configuration for MIMO eigenbeam space division multiplexing,” IEICE Society Conference, B-1-219, Sept. 2005.

原田 博司, 安 昌俊, 高橋 賢, 神尾 享秀, 三瓶 政一, “通信システム、通信方法、基地局、および移動局,” 特許公開2005-252964, Sept. 15, 2005.

Satoshi Takahashi, Chang-Jun Ahn, Hiroshi Harada, and Yukiyoshi Kamio, “Effect of delay spread enhancement in MIMO eigenbeam space division multiplexing transmission,” IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, vol.E88-A, no.7, pp.1931-1935, July 2005. DOI: 10.1093/ietfec/e88-a.7.1931.
URL: http://search.ieice.org/bin/summary.php?id=e88-a_7_1931&category=A&lang=E&year=2005&abst=

Chang-Jun Ahn, Satoshi Takahashi, Hiroshi Harada, Yukiyoshi Kamio, and Iwao Sasase, “Adaptive subcarrier block modulation with differentially modulated pilot symbol assistance for downlink OFDM using uplink delay spread,” IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, vol.E88-A, no.7, pp.1889-1896, July 2005. DOI: 10.1093/ietfec/e88-a.7.1889.
URL: http://search.ieice.org/bin/summary.php?id=e88-a_7_1889&category=A&lang=E&year=2005&abst=

高橋 賢, 原田 博司, 安 昌俊, “マイクロ波帯移動通信における遅延広がりのアンテナチルト依存性,” 電子情報通信学会技術研究報告, AP2005-28, May 2005.
Satoshi Takahashi, Hiroshi Harada, and Chang-Jun Ahn, “Antenna tilt dependence on delay spread in microwave mobile communications,” IEICE Technical Report, AP2005-28, May 2005.

Toshiro Suzuki, Ken Takei, Satoshi Takahashi, Hiroshi Usami, and Yuuji Ishida, Wireless communication method and system using beam direction-variable antenna," United States Patent, 6,879,845, Apr. 12, 2005.
URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6879845.PN.&OS=PN/6879845&RS=PN/6879845

高橋 賢, 安 昌俊, 神尾 享秀, 原田 博司, “MIMO固有ビーム伝送における変調多値数の決定法,” 電子情報通信学会総合大会, B-1-251, March 2005.
Satoshi Takahashi, Chang-Jun Ahn, Yukiyoshi Kamio, and Hiroshi Harada, “A determination method of substream modulation levels for MIMO eigenbeam space division multiplexing,” IEICE General Conference, B-1-251, March 2005.

Chang-Jun Ahn, Satoshi Takahashi, and Hiroshi Harada, “Differential modulated pilot symbol assisted adaptive OFDM for reducing the MLI with predicted FBI,” IEICE Transactions on Communications, vol.E88-B, no.2, pp.436-442, Feb. 2005.
URL: http://search.ieice.org/bin/summary.php?id=e88-b_2_436&category=B&lang=E&year=2005&abst=

Satoshi Takahashi, Chang-Jun Ahn, Hiroshi Harada, and Yukiyoshi Kamio, “Stochastic determination method of substream modulation levels for MIMO eigenbeam space division multiplexing,” 2005 IEEE International Conference on Personal Wireless Communications (ICPWC ‘05), pp.343-347, New Delhi, Jan. 2005.

Chang-Jun Ahn, Satoshi Takahashi, Hiroshi Harada, and Yukiyoshi Kamio, “Enhancement of MLD for SDM/OFDM using power imbalance of polarization and pre-phase distortion scheme,” 2005 IEEE International Conference on Personal Wireless Communications (ICPWC ‘05), pp.104-108, New Delhi, Jan. 2005.

Hiroshi Harada, Chang-Jun Ahn, and Satoshi Takahashi, “100 Mbps and beyond hotspot communication prototypes for next generation mobile communication system,” 2005 IEEE International Conference on Personal Wireless Communications (ICPWC ‘05), pp.24-28, New Delhi, Jan. 2005.

Chang-Jun Ahn, Satoshi Takahashi, and Hiroshi Harada, “Adaptive sub-carrier block modulation with differentially modulated pilot symbol assistance for down-link OFDM using up-link delay spread,” IEICE Technical Report, RCS2004-298, Jan. 2005.

Satoshi Takahashi, Chang-Jun Ahn, Hiroshi Harada, and Yukiyoshi Kamio, “Stochastic prediction of transmission errors in MIMO eigenbeam space division multiplexing,” IEICE Technical Report, RCS2004-294, Jan. 2005.

原田 博司, 船田 龍平, 安 昌俊, 高橋 賢, 澤田 学, “逐次型伝搬路推定を用いた高速移動OFDMパケット無線伝送システム〜概要と基礎伝送結果〜,” 電子情報通信学会技術研究報告, RCS2004-261, Jan. 2005.
Hiroshi Harada, Ryuhei Funada, Chang-Jun Ahn, Satoshi Takahashi, and Manabu Sawada, “OFDM packet transmission system with a sequentially updated channel estimation algorithm -concept and fundamental transmission characteristics,” IEICE Technical Report, RCS2004-261, Jan. 2005.

2004

Satoshi Takahashi, Akihito Kato, Katsuyoshi Sato, and Masayuki Fujise, “Distance dependence of path loss for millimeter wave inter-vehicle communications,” Radioengineering, vol.13, no.4, pp.8-13, Dec. 2004.
URL: http://www.radioeng.cz/fulltexts/2004/04_04_08_13.pdf

Chang-Jun Ahn, Yukiyoshi Kamio, Satoshi Takahashi, and Hiroshi Harada, “Reverse link performance improvement for a wideband OFDM using Alamouti coded heterogeneous polarization antennas,” IEICE Transactions on Communications, vol.E87-B, no. 11, pp.3281-3288, Nov. 2004.
URL: http://search.ieice.org/bin/summary.php?id=e87-b_11_3281&category=B&lang=E&year=2004&abst=

Satoshi Takahashi, Hiroshi Harada, Chang-Jun Ahn, and Yukiyoshi Kamio, “Site-dependent BER due to MIMO beamforming predicted by using ray tracing,” IEEE TENCON 2004, vol.C, pp.204-207, Chiang Mai, Nov. 2004.

Chang-Jun Ahn, Yukiyoshi Kamio, Satoshi Takahashi, and Hiroshi Harada, “Differential modulated pilot symbol assisted adaptive OFDM for reducing the modulation level information,” IEEE TENCON 2004, vol.B, pp.577-580, Chiang Mai, Nov. 2004.

Satoshi Takahashi, Hiroshi Harada, Chang-Jun Ahn, and Yukiyoshi Kamio, “Path loss dependence of delay spread in MIMO transmission,” 7th International Symposium on Wireless Multimedia Communications (WPMC) 2004, vol.1, MA1-3, Abano Terme, Sept. 2004.

Hiroshi Harada, Chang-Jun Ahn, Satoshi Takahashi, “Experimental performance analysis of parallel communicated PR-DSMA protocol for 100 Mbps and beyond wireless access systems,” 60th IEEE Vehicular Technology Conference (VTC2004-Fall), vol.7, pp.4978-4982, Sept. 2004.

Hiroshi Harada, Chang-Jun Ahn, Satoshi Takahashi, Yukiyoshi Kamio, and Seiichi Sampei, “Dynamic parameter controlled orthogonal frequency and time division multiple access,” 15th IEEE International Symposium on Personal Wireless Communications (PIMRC 2004), vol.4, pp.2648-2652, Barcelona, Sept. 2004.

Chang-Jun Ahn, Satoshi Takahashi, Hiroshi Harada, and Yukiyoshi Kamio, “Differential modulated pilot symbol assisted adaptive OFDM for reducing the MLI transmission,” IEICE Society Conference, BS-8-4, Sept. 2004.

高橋 賢, 原田 博司, 安 昌俊, 神尾 享秀, “MIMO固有ビーム伝送における遅延広がり強調の効果,” 電子情報通信学会ソサイエティ大会, B-1-180, Sept. 2004.
Satoshi Takahashi, Hiroshi Harada, Chang-Jun Ahn, and Yukiyoshi Kamio, “An effect of delay spread enhancement in MIMO eigenbeam transmission,” IEICE Society Conference, B-1-180, Sept. 2004.

Satoshi Takahashi, Hiroshi Harada, Chang-Jun Ahn, H. Iwai, K. Yonezawa, and T. Maeyama, “Path loss dependence of delay spread at 5 GHz in inhomogeneous suburban environments,” 2004 International Symposium on Antennas and Propagation (ISAP), Sendai, pp.725-728, Aug. 2004.

Chang-Jun Ahn, Yukiyoshi Kamio, Satoshi Takahashi, and Hiroshi Harada, “Heterogeneous polarization transmission diversity based on Alamouti coded OFDM,” 11th IEEE International Conference on Telecommunications (ICT 2004), Fortaleza, Aug. 2004.

Chang-Jun Ahn, Satoshi Takahashi, and Hiroshi Harada, “Differential modulated pilot symbol assisted adaptive OFDM for reducing the MLI with predicted FBI,” IEICE Technical Report, RCS2004-109, July 2004.

Chang-Jun Ahn, Yukiyoshi Kamio, Satoshi Takahashi, and Hiroshi Harada, “Reverse link performance improvement for a wideband OFDM using Alamouti coded heterogeneous polarization antennas,” 9th IEEE International Symposium on Computers and Communication (ISCC 2004), vol.2, pp.702-707, Alexandria, June 2004.

高橋 賢, 原田 博司, 安 昌俊, 神尾 享秀, “レイトレース法によるMIMO伝送の誤り率場所依存性の推定,” 電子情報通信学会技術研究報告, AP2004-14, May 2004.
Satoshi Takahashi, Hiroshi Harada, Chang-Jun Ahn, and Yukiyoshi Kamio, “Site dependence BER prediction of MIMO transmission by using ray tracing,” IEICE Technical Report, AP2004-14, May 2004.

原田 博司, 安 昌俊, 高橋 賢, 神尾 享秀, 三瓶 政一, “Dynamic parameter controlled OF/TDMAによる高速移動広帯域無線アクセスシステム,” 電子情報通信学会総合大会, B-5-64, March 2004.
Hiroshi Harada, Chang-Jun Ahn, Satoshi Takahashi, Yukiyoshi Kamio, and Seiichi Sampei, “High-mobility broadband wireless access system by dynamic parameter controlled OF/TDMA,” IEICE General Conference, B-5-64, March 2004.

Chang-Jun Ahn, Yukiyoshi Kamio, Satoshi Takahashi, and Hiroshi Harada, “Imbalanced power of polarization based antenna-phase controlled SDM/OFDM system,” IEICE General Conference, B-5-63, March 2004.

高橋 賢, 原田 博司, 安 昌俊, 神尾 享秀, “レイトレース法によるMIMOチャネル容量の推定,” 電子情報通信学会総合大会, B-1-223, March 2004.
Satoshi Takahashi, Hiroshi Harada, Chang-Jun Ahn, and Yukiyoshi Kamio, “MIMO channel capacity prediction by using ray tracing,” IEICE General Conference, B-1-223, March 2004.

原田 博司, 安 昌俊, 高橋 賢, 神尾 享秀, “Dynamic parameter controlled OFDMによる新世代移動通信システム,” 電子情報通信学会技術研究報告, RCS2003-284, Jan. 2004.
Hiroshi Harada, Chang-Jun Ahn, Satoshi Takahashi, Yukiyoshi Kamio, and Seiichi Sampei, “New generation mobile communication system by dynamic parameter controlled OFDM,” IEICE Technical Report, RCS2003-284, Jan. 2004.

Chang-Jun Ahn, Yukihide Kamio, Satoshi Takahashi, and Hiroshi Harada, “Antenna-phase controlled SDM/OFDM with polarization diversity for dynamic parameter controlled OFDM system,” IEICE Technical Report, RCS2003-283, Jan. 2004.

Chang-Jun Ahn, Yukiyoshi Kamio, Satoshi Takahashi, and Hiroshi Harada, “Reverse link performance improvement for dynamic parameter controlled OFDM using Alamouti coded heterogeneous polarization antennas,” IEICE Technical Report, RCS2003-248, Jan. 2004.

2003

Katsuyoshi Sato, Satoshi Takahashi, Jun Sato, Tadamasa Fukae, T. Horimatsu, and Masayuki Fujise, “Joint research project on millimeter-wave communication system for inter-vehicle communication at Yokosuka Research Park,” The 10th World Congress and Exhibition on Intelligent Transport Systems and Services (ITSWC2003), pp.1-12, Nov. 2003.

Satoshi Takahashi, Akihito Kato, Katsuyoshi Sato, Masayuki Fujise, “Distance dependence of path loss for millimeter wave inter-vehicle communications,” IEEE Vehicular Technology Conference (VTC ‘03-Fall), pp.26-30, Orland, Oct. 2003.

高橋 賢, “マルチパス環境における伝搬損測定の不確定性,” 日本学術会議電波科学研究連絡委員会 第478回F分科会資料(URSI-F分科会), Oct. 2003.
Satoshi Takahashi, “Uncertainty in propagation loss measurements in multipath environments,” The 478th URSI-F Document in Japan, Oct. 2003.

武井 健, 高橋 賢, “音声およびデータサービス用無線通信システム,” 特許公開2003-283408, Oct. 3, 2003.

高橋 賢, “端末に対して送信する信号の伝送速度または送信電力を変化させる無線通信装置およびその信号送信方法,” 特許公開2003-163632, June 6, 2003.

澤 良次, 深江 唯正, 佐藤 勝善, 高橋 賢, 加藤 明人, 藤瀬 雅行, “SS方式レーダをベースにした車車間通信システムの実験検討,” 電子情報通信学会技術研究報告, ITS2003-6, May 2003.
Yoshitsugu Sawa, Tadamasa Fukae, Katsuyoshi Sato, Satoshi Takahashi, Akihito Kato, and Masayuki Fujise, “Experimental study of inter-vehicle communication based on spread sprectrum radar,” IEICE Technical Report, ITS2003-6, May 2003.

深江 唯正, 澤 良次, 佐藤 勝善, 高橋 賢, 加藤 明人, 藤瀬 雅行, “SS方式レーダをベースにした車車間通信システムの提案,” 電子情報通信学会技術研究報告, ITS2003-5, May 2003.
Tadamasa Fukae, Yoshitsugu Sawa, Katsuyoshi Sato, Satoshi Takahashi, Akihito Kato, and Masayuki Fujise, “A proposal of inter-vehicle communication based on spread sprectrum radar,” IEICE Technical Report, ITS2003-5, May 2003.

佐藤 勝善, 加藤 明人, 高橋 賢, 藤瀬 雅行, 堀松 哲夫, 佐藤 純, 木田 弘幸, 深江 唯正, 田村 禎啓, 赤澤 逸人, “YRPにおけるミリ波帯車々間通信実証実験の報告,” 電子情報通信学会技術研究報告, ITS2003-4, May 2003.
Katsuyoshi Sato, Akihito Kato, Satoshi Takahashi, Masayuki Fujise, Tstsuo Horimatsu, Jun Sato, Tadamasa Fukae, Sadahiro Tamura, and Hayato Akazawa, “Inter-vehicle communication systems using millimeter wave band -joint research and experimental activities on ITS at YRP,” IEICE Technical Report, ITS2003-4, May 2003.

川上 茂, 加藤 明人, 佐藤 勝善, 高橋 賢, 藤瀬 雅行, “60GHzミリ波車々間通信における高速走行時のフェージング特性,” 電子情報通信学会技術研究報告, AP2003-28, May 2003.
Shigeru Kawakami, Akihito Kato, Katsuyoshi Sato, Satoshi Takahashi, Masayuki Fujise, and Tetsuo Horimatsu, “Fading characteristics of 60 GHz band inter-vehicle communications running at high speed,” IEICE Technical Report, AP2003-28, May 2003.

高橋 賢, 加藤 明人, 佐藤 勝善, 藤瀬 雅行, “60GHzミリ波車々間通信における伝搬損距離特性,” 電子情報通信学会技術研究報告, AP2003-5, May 2003.
Satoshi Takahashi, Akihito Kato, Katsuyoshi Sato, and Masayuki Fujise, “Distance dependence of path loss for 60 GHz millimeter wave inter-vehicle communications,” IEICE Technical Report, AP2003-5, May 2003.

高橋 賢, 加藤 明人, 佐藤 勝善, 藤瀬 雅行, “ミリ波車両間通信における実測伝搬損の解析例,” 電子情報通信学会総合大会, B-1-39, March 2003.
Satoshi Takahashi, Akihito Kato, Katsuyoshi Sato, and Masayuki Fujise, “An example of measured path loss analysis for millimeter wave inter-vehicle communications,” IEICE General Conference, B-1-39, March 2003.

2002

高橋 賢, 加藤 明人, 佐藤 勝善, 藤瀬 雅行, “車両間ミリ波通信における空間ダイバーシチの効果,” 電子情報通信学会ソサイエティ大会, B-1-23, Sept. 2002.
Satoshi Takahashi, Akihito Kato, Katsuyoshi Sato, and Masayuki Fujise, “An effect of space diversity for inter-vehicle millimeter wave communications,” IEICE Society Conference, B-1-23, Sept. 2002.

鈴木 俊朗, 高橋 賢, 武井 健, “無線通信方法及びビーム方向可変型アンテナを用いた無線通信システム,” 特許公開2002-232350, Aug. 16, 2002.

鈴木 俊郎, 高橋 賢, 中川 准一, 武井 健, “セルラシステム及び基地局,” 特許公開2002-58063, Feb. 22, 2002.

2001

高橋 賢, “電波受信強度シミュレーション方法,” 特許第3256085号, Nov. 30, 2001.

Hironari Masui, Masanori Ishii, Satoshi Takahashi, Hiroyuki Shimizu, Takehiko Kobayashi, and Masami Akaike, “Microwave propagation characteristics in an urban quasi line-of-sight environment under different traffic conditions,” IEICE Transactions on Communications, vol.E84-B, no.5, pp.1431-1439, May 2001.
URL: http://search.ieice.org/bin/summary.php?id=e84-b_5_1431&category=B&lang=E&year=2001&abst=

2000

鹿毛 豪藏, 高橋 幸一, 高橋 賢, 増井 裕也, 小林 岳彦, “ 見通し内マイクロ波帯市街地伝搬の伝搬損モデルとフェージングマージン,” 電子情報通信学会論文誌(B), vol.J83-B, no.1, pp.144-148, Jan. 2000.
Kouzou Kage, Koichi Takahashi, Satoshi Takahashi, Hironari Masui, and Takehiko Kobayahi, “Path loss model and fading margins of microwave line-of-sight propagation in urban area,” IEICE Transactions on Communications (Japanese Ed.), vol.J83-B, no.1, pp.144-148, Jan. 2000.
URL: http://search.ieice.org/bin/summary.php?id=j83-b_1_144&category=B&lang=J&year=2000&abst=

Hironari Masui, Masanori Ishii, Satoshi Takahashi, Hiroyuki Shimizu, and Takehiko Kobayashi, “Microwave propagation characteristics in an urban LOS environment in different traffic conditions,” 2000 IEEE AP-S International Symposium, vol.2, pp.1150-1153, Salt Lake City, July 2000.

Satoshi Takahashi, Hiroyuki Shimizu, Masanori Ishii, Hironari Masui, and Takehiko Kobayashi, “Variation-interval prediction of median-path loss in multipath environments using measured delay profiles,” Millennium Conference on Antennas & Propagation (AP-2000), no.2P7, Davos, Apr. 2000.

高橋 賢, 鹿毛 豪藏, “電界強度測定装置,” 特許第3053779号, Apr. 7, 2000.

Hironari Masui, Masanori Ishii, Satoshi Takahashi, Hiroyuki Shimizu, and Takehiko Kobayashi, “Difference of break-point characteristics due to mobile antenna heights in microwave urban LOS propagation,” 2000 International Zurich Seminar on Broadband Communications (IZS 2000), pp.223-228, Zurich, Feb. 2000.

1999

Hironari Masui, Koichi Takahashi, Satoshi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “Distance dependence of microwave delay spreads measured in urban quasi line-of-site environments,” IEICE Transactions on Communications, vol.E82-B, no.12, pp.1997-2003, Dec. 1999.
URL: http://search.ieice.org/bin/summary.php?id=e82-b_12_1997&category=B&lang=E&year=1999&abst=

Satoshi Takahashi, Takehiko Kobayashi, Kouzou Kage, Koichi Takahashi, and Hironari Masui, “Stochastic prediction of transmission performance in mobile communication systems employing anti-multipath techniques in urban propagation environments,” IEICE Transactions on Communications, vol.E82-B, no.12, pp.1987-1996, Dec. 1999. (2000 IEEE Antennas and Propagation Society Japan Chapter Young Engineer Award受賞論文)
Satoshi Takahashi, Takehiko Kobayashi, Kouzou Kage, Koichi Takahashi, and Hironari Masui, “Stochastic prediction of transmission performance in mobile communication systems employing anti-multipath techniques in urban propagation environments,” IEICE Transactions on Communications, vol.E82-B, no.12, pp.1987-1996, Dec. 1999. (This paper was receved the 2000 IEEE Antennas and Propagation Society Japan Chapter Young Engineer Award)
URL: http://search.ieice.org/bin/summary.php?id=e82-b_12_1987&category=B&lang=E&year=1999&abst=

Satoshi Takahashi, Koichi Takahashi, Hironari Masui, Kouzou Kage, and Takehiko Kobayashi, “Performance of parallel transmission applied to broadband mobile communication systems in urban multipath environments,” The 50th IEEE Vehicular Technology Conference (VTC ‘99-Fall), vol.2, pp.1028-1032, Amsterdam, Sept. 1999.

高橋 賢, 清水 裕之, 石井 雅典, 増井 裕也, 小林 岳彦, “マイクロ波帯市街地伝搬における中央値変動幅の推定,” 電子情報通信学会ソサイエティ大会, B-1-14, Sept. 1999.
Satoshi Takahashi, Hiroyuki Shimizu, Masanori Ishii, Hironari Masui, and Takehiko Kobayashi, “Prediction of median-fluctuation intervals in microwave urban propagation,” IEICE Society Conference, B-1-14, Sept. 1999.

増井 裕也, 石井 雅典, 高橋 賢, 清水 裕之, 小林 岳彦, “マイクロ波帯市街地伝搬損失特性における交通量の影響,” 電子情報通信学会ソサイエティ大会, B-1-13, Sept. 1999.
Hironari Masui, Masanori Ishii, Satoshi Takahashi, Hiroyuki Shimizu, and Takehiko Kobayashi, “Effects of traffic on path-loss characteristics in microwave urban propagation,” IEICE Society Conference, B-1-13, Sept. 1999.

清水 裕之, 増井 裕也, 高橋 賢, 石井 雅典, 小林 岳彦, “マイクロ波帯見通し内および見通し外郊外地伝搬における伝搬損失および遅延特性,” 電子情報通信学会ソサイエティ大会, B-1-12, Sept. 1999.
Hiroyuki Shimizu, Hironari Masui, Satoshi Takahashi, Masanori Ishii, and Takehiko Kobayashi, “LOS and NLOS path-loss and delay characteristics in microwave suburban propagation,” IEICE Society Conference, B-1-12, Sept. 1999.

石井 雅典, 増井 裕也, 高橋 賢, 清水 裕之, 小林 岳彦, “マイクロ波帯郊外地伝搬における見通し外伝搬損失測定,” 電子情報通信学会ソサイエティ大会, B-1-11, Sept. 1999.
Masanori Ishii, Hironari Masui, Satoshi Takahashi, Hiroyuki Shimizu, and Takehiko Kobayashi, “Measurements of non-line-of-sight loss in microwave suburban propagation,” IEICE Society Conference, B-1-11, Sept. 1999.

Hironari Masui, Koichi Takahashi, Satoshi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “Microwave delay characteristics on urban urban line-of-site roads,” 16th General Assembly of URSI, pp.368, Toronto, Aug. 1999.

Takehiko Kobayashi, Hironari Masui, Koichi Takahashi, Satoshi Takahashi, and Kouzou Kage, “Delay profile measurement system for microwave mobile communication systems and delay characteristics in an urban environment,” 1999 IEEE Radio and Wireless Conference (RAWCON ‘99), Denver, Aug. 1999.

高橋 賢, “ビット誤り率測定方法および装置,” 特許第2968250号, Aug. 20, 1999.

Koichi Takahashi, Hironari Masui, Satoshi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “Path loss modeling of line-of-sight microwave urban propagation with low-height antenna mobile stations,” IEICE Transactions on Electronics, vol.E82-C, no.7, pp.1330-1333, July 1999.
URL: http://search.ieice.org/bin/summary.php?id=e82-c_7_1330&category=C&lang=E&year=1999&abst=

Hironari Masui, Koichi Takahashi, Satoshi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “Delay profile measurement system for microwave broadband transmission and analysis of delay characteristics in an urban environment,” IEICE Transactions on Electronics, vol.E82-C, no.7, pp.1287-1292, July 1999. (This paper was received the Telecommunication Systems Technical Award from Denki Tsushin Fukyu Zaidan.)
URL: http://search.ieice.org/bin/summary.php?id=e82-c_7_1287&category=C&lang=E&year=1999&abst=

Hironari Masui, Koichi Takahashi, Satoshi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “Difference of path-loss characteristics due to mobile antenna heights in microwave urban propagation,” IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, vol.E82-A, no.7, pp.1144-1150, July 1999.
URL: http://search.ieice.org/bin/summary.php?id=e82-a_7_1144&category=A&lang=E&year=1999&abst=

高橋 賢, “特性関数法を用いた多重波環境下での無線伝送特性の評価法,” 電子情報通信学会論文誌(B), vol.J82-B, no.7, pp.1384-1393, July 1999. (English translation is available at Satoshi Takahashi, “Performance evaluation of radio transmission in multipath environments using characteristic function method,” Electronics and Communications in Japan, Part 1, vol.84, no.9, pp.64-73, Sept. 2001.)
Satoshi Takahashi, “Performance evaluation of radio transmission in multipath propagation environments using characteristic function method,” IEICE Transactions on Communications (Japanese Ed.), vol.J82-B, no.7, pp.1384-1393, July 1999. (English translation is available at Satoshi Takahashi, “Performance evaluation of radio transmission in multipath environments using characteristic function method,” Electronics and Communications in Japan, Part 1, vol.84, no.9, pp.64-73, Sept. 2001.)
URL: http://search.ieice.org/bin/summary.php?id=j82-b_7_1384&category=B&lang=J&year=1999&abst=
2nd PDF

鹿毛 豪藏, 増井 裕也, 高橋 幸一, 高橋 賢, 小林 岳彦, “見通し内マイクロ波帯市街地伝搬における瞬時変動の統計的性質,” 電子情報通信学会論文誌(B), vol.J82-B, no.6, pp.1204-1210, June 1999.
Kouzou Kage, Hironari Masui, Koichi Takahashi, Satoshi Takahashi, and Takehiko Kobayashi, “Fading characteristics of microwave line-of-sight propagation in urban area,” IEICE Transactions on Communications (Japanese Ed.), vol.J82-B, no.6, pp.1204-1210, June 1999.
URL: http://search.ieice.org/bin/summary.php?id=j82-b_6_1204&category=B&lang=J&year=1999&abst=

関根 勇樹, 島野 健一郎, 坂口 啓, 高田 潤一, 荒木 純道, 高橋 賢, 増井 裕也, 高橋 幸一, 鹿毛 豪藏, 小林 岳彦, “遅延プロファイル測定装置とアレーアンテナを用いた角度遅延プロファイル特性の測定実験,” 日本学術会議電波科学研究連絡委員会 第435回F分科会資料(URSI-F分科会), June 1999.
Yuki Sekine, Kenichiro Shimano, Kei Sakaguchi, Junichi Takada, Kiyomichi Araki, Satoshi Takahashi, Hironari Masui, Koichi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “Measurement experiment on angular delay profile characteristics by using delay profile measurement equipment and array antenna,” The 435th URSI-F Document in Japan, June 1999.

Satoshi Takahashi, Koichi Takahashi, Kouzou Kage, Takehiko Kobayashi, and Hironari Masui, “Performance prediction of digital mobile communication systems in urban multipath environments,” The 49th IEEE Vehicular Technology Conference (VTC ‘99), vol.2, pp.586-589, Houston, May 1999.

増井 裕也, 高橋 幸一, 高橋 賢, 鹿毛 豪藏, 小林 岳彦, “マイクロ波帯市街地伝搬遅延特性の検討,” 日本学術会議電波科学研究連絡委員会 第433回F分科会資料(URSI-F分科会), Apr. 1999.
Hironari Masui, Koichi Takahashi, Satoshi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “On microwave urban delay spread characteristics,” The 433th URSI-F Document in Japan, Apr. 1999.

Koichi Takahashi, Hironari Masui, Satoshi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “Delay spread in line-of-sight microwave urban propagation,” The Progress in Electromagnetics Research Symposium (PIERS 1999), vol.2, pp.603, Taipei, March 1999.

Hironari Masui, Koichi Takahashi, Satoshi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “Delay profile measurement system for microwave broadband transmission,” The Progress in Electromagnetics Research Symposium (PIERS 1999), vol.2, pp.601, Taipei, March 1999.

高橋 賢, 鹿毛 豪藏, 高橋 幸一, 増井 裕也, 小林 岳彦, “マイクロ波帯市街地伝搬環境におけるBPSK-RZ伝送特性の評価,” 電子情報通信学会総合大会, B-1-49, March 1999.
Satoshi Takahashi, Kouzou Kage, Koichi Takahashi, Hironari Masui, and Takehiko Kobayashi, “Estimation of BPSK-RZ transmission performance in microwave urban propagation environments,” IEICE General Conference, B-1-49, March 1999.

増井 裕也, 高橋 幸一, 高橋 賢, 鹿毛 豪藏, 小林 岳彦, 中嶋 清裕, “マイクロ波帯市街地伝搬における見通し外伝搬損失測定,” 電子情報通信学会総合大会, B-1-48, March 1999.
ironari Masui, Koichi Takahashi, Satoshi Takahashi, Kouzou Kage, Takehiko Kobayashi, and Kiyohiro Nakajima, “Measurements of non-line-of-sight loss in microwave urban propagation,” IEICE General Conference, B-1-48, March 1999.

高橋 幸一, 高橋 賢, 増井 裕也, 鹿毛 豪藏, 小林 岳彦, 今井 輝幸, “マイクロ波帯郊外地伝搬における伝搬損失および遅延プロファイルの測定,” 電子情報通信学会総合大会, B-1-47, March 1999.
Koichi Takahashi, Satoshi Takahashi, Hironari Masui, Kouzou Kage, Takehiko Kobayashi, and Teruyuki Imai, “Measurements of loss and delay profile in microwave suburban propagation,” IEICE General Conference, B-1-47, March 1999.

鹿毛 豪藏, 高橋 賢, 高橋 幸一, 増井 裕也, 小林 岳彦, “マイクロ波帯移動伝搬における到来角測定,” 電子情報通信学会総合大会, B-1-46, March 1999.
Kouzou Kage, Satoshi Takahashi, Koichi Takahashi, Hironari Masui, and Takehiko Kobayashi, “Measurements of direction of arrival in microwave mobile propagation,” IEICE General Conference, B-1-46, March 1999.

Satoshi Takahashi, Koichi Takahashi, Hironari Masui, Kouzou Kage, and Takehiko Kobayashi, “RAKE reception evaluation for microwave mobile propagation using characteristic function method,” 1999 IEEE International Conference on Personal Wireless Communications (ICPWC ‘99), pp.101-104, Jaipur, Feb. 1999.

鹿毛 豪藏, 高橋 幸一, 高橋 賢, 増井 裕也, 小林岳彦, “見通し内マイクロ波帯市街地伝搬のフェージングマージン,” 電子情報通信学会技術研究報告, AP98-158, Feb. 1999.
Kouzou Kage, Koichi Takahashi, Satoshi Takahashi, Hironari Masui, and Takehiko Kobayashi, “Fading margins of microwave line-of-sight propagation in urban area,” IEICE Technical Report, AP98-158, Feb. 1999.

増井 裕也, 高橋 幸一, 高橋 賢, 鹿毛 豪藏, 小林 岳彦, “マイクロ波帯市街地伝搬遅延特性の移動局アンテナ高依存性の検討,” 電子情報通信学会技術研究報告, AP98-133, Jan. 1999.
Hironari Masui, Koichi Takahashi, Satoshi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “Effects of mobile antenna height on delay spread in microwave urban propagation,” IEICE Technical Report, AP98-133, Jan. 1999.

1998

Satoshi Takahashi, Kouzou Kage, Hironari Masui, Koichi Takahashi, and Takehiko Kobayashi, “Numerical estimation of eye aperture ratio in multipath environments,” The First International Symposium on Wireless Personal Communications (WPMC ‘98), pp.370-373, Yokosuka, Nov. 1998.

高橋 幸一, 増井 裕也, 高橋 賢, 鹿毛 豪藏, 小林 岳彦, “低アンテナ高移動機に対する市街地見通し内マイクロ波伝搬損失,” 電子情報通信学会技術研究報告, AP98-86, Oct. 1998.
Koichi Takahashi, Hironari Masui, Satoshi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “Path loss characteristics of line-of-sight microwave propagation with low height mobile station antenna,” IEICE Technical Report, AP98-86, Oct. 1998.
URL: https://ci.nii.ac.jp/naid/110003248388

3.35GHz, 8.45GHzおよび15.75GHzのマイクロ波を用いて, 東京都心部において低アンテナ高移動機による伝搬損距離特性の測定実験を行い, 道路幅の影響および移動機アンテナ高依存性について検討した.移動機アンテナ高は0.5m, 1.6mおよび2.7mの3通りである.道路幅または移動局アンテナ高による影響を考慮し, 従来式および提案式を用いて実測データの解析を行った.その結果, 移動機アンテナ高が低い場合, 新たに提案する簡易式でも十分に伝搬損距離特性の評価が可能であることがわかった.
This paper discussed the path-loss models in street microcell environments at microwave frequencies. Measurements were made in metropolitan Tokyo at 3.35, 8.45GHz and 15.75GHz with reception antenna heights of 0.5, 1.6 and 2.7m. The measured data is analysed by using a conventional model and a newly proposed model. The analysis forcuses on the effects of road width and reception antenna height. The proposed simple model better fits the measured data, especially for the low antenna height.

高橋 賢, 高橋 幸一, 鹿毛 豪藏, 小林 岳彦, 増井 裕也, “マイクロ波帯市街地伝搬の到来波数距離特性,” 電子情報通信学会ソサイエティ大会, B-1-29, Sept. 1998. (電子情報通信学会学術奨励賞受賞論文)
Satoshi Takahashi, Koichi Takahashi, Kouzou Kage, Takehiko Kobayashi, and Hironari Masui, “Distance dependence of multipath radiowave numbers in microwave urban propagation,” IEICE Society Conference, B-1-29, Sept. 1998. (This paper was received the IEICE Research Award)
URL: https://ci.nii.ac.jp/naid/110003344890

増井 裕也, 高橋 幸一, 高橋 賢, 鹿毛 豪藏, 小林 岳彦, “マイクロ波帯市街地伝搬遅延特性の移動局アンテナ高依存性,” 電子情報通信学会ソサイエティ大会, B-1-28, Sept. 1998.
Hironari Masui, Koichi Takahashi, Satoshi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “Influence of mobile antenna height on delay spread,” IEICE Society Conference, B-1-28, Sept. 1998.
URL: https://ci.nii.ac.jp/naid/110003344889

高橋 幸一, 増井 裕也, 高橋 賢, 鹿毛 豪藏, 小林 岳彦, “マイクロ波帯市街地伝搬遅延特性の周波数依存性,” 電子情報通信学会ソサイエティ大会, B-1-27, Sept. 1998.
Koichi Takahashi, Hironari Masui, Satoshi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “Influence of frequency on delay spread in microwave urban propagation,” IEICE Society Conference, B-1-27, Sept. 1998.
URL: https://ci.nii.ac.jp/naid/110003344888

高橋 賢, 高橋 幸一, 鹿毛 豪藏, 小林 岳彦, 増井 裕也, “マイクロ波帯市街地伝搬における到来波数および伝送特性の推定,” 電子情報通信学会技術研究報告, RCS98-80, Sept. 1998.
Satoshi Takahashi, Koichi Takahashi, Kouzou Kage, Takehiko Kobayashi, and Hironari Masui, “Radiowave numbers in microwave urban radio propagation and transmission performance prediction,” IEICE Technical Report, RCS98-80, Sept. 1998.
URL: https://ci.nii.ac.jp/naid/110003305126

本報告では, 市街地において測定した遅延プロファイルの距離特性を解析する.測定に用いた周波数は3.35GHz, 8.45GHz, および15.75GHzであり, 擬似雑音符号の拡散速度は50Mchip/sである.測定した遅延プロファイルから電波到来波数の距離依存性を抽出し, 拡散速度より低い符号速度でのビット誤り率とアイ開口率を推定した.市街地見通し内において, 距離に対する到来波数は一様とならず, 主波が支配的になる場所も多く存在することがわかった.ビット誤り率とアイ開口率の推定から, 送信点の近傍においても伝送特性の局所的な劣化が生じることが明らかになった.
This report analyzes the distance dependence of delay profiles measured in an uraban area. Frequencies of 3.35 GHz, 8.45 GHz and 15.75 GHz and 50 Mchip/s psuedo-noise chip rate are used in this measurement. The site-dependence of radiowave numbers are extracted from the measured delay profiles, and then the bit error rates and eye aperture ratios are predicted at a lower symbol rate compared to the chip rate. The evaluations show that radiowave number is not distributed uniformly with respect to distance and that there are several locations where the strongest wave is dominant. The bit-error-rate and eye-aperture-ratio estimations show that partial degradation of the transmission performance occurs even in near the transmission point.

Satoshi Takahashi and Yoshihide Yamada, “Propagation-loss prediction using ray tracing with a random-phase technique,” IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, vol.E81-A, no.7, pp.1445-1451, July 1998.
URL: http://search.ieice.org/bin/summary.php?id=e81-a_7_1445&category=A&lang=E&year=1998&abst=

For mobile telecommunication systems, it is important to accurately predict the propagation-path loss in terms of the estimation of the radiowave coverage area. The propagation-path loss has been estimated in a median obtained spatially from many received amplitudes (envelopes) within a region of several tens times as long as the wavelength, rather than in the envelopes themselves. Although ray tracing can obtain the envelopes and their median that reflect the site-dependent characteristics, the estimated median sometimes does not agree with the measured one. Therefore, the accuracy improvement has been expected. In this paper, an accuracy improvement is achieved by substituting a median with random phases for the median obtained spatially from many envelopes. The characteristic function method is used to obtain the cumulative distribution function and the median analytically where the phases are randomized. In a multipath environment, the phase-estimation error accompanying the location error of the ray tracing input influences the spatially obtained median. The phase-randomizing operation reduces the effects of the phase-estimation error on the median prediction. According to our estimation, improvements in accuracy of 4.9 dB for the maximum prediction error and 2.9 dB for the RMS prediction error were achieved. In addition, a probability-based cell-design method that takes the radiowave arrival probability and the interference probability into consideration is possible by using the percentiles obtained by the characteristic function method and the cell-design examples are shown in this paper.

鹿毛 豪藏, 増井 裕也, 高橋 幸一, 高橋 賢, 小林 岳彦, “マイクロ波帯市街地伝搬における瞬時変動特性の統計的性質,” 電子情報通信学会技術研究報告, AP98-33, July 1998.
Kouzou Kage, Hironari Masui, Koichi Takahashi, Satoshi Takahashi, and Takehiko Kobayashi, “Statistical fading characteristics of urban microwave radio propagation,” IEICE Tecnical Report, AP98-33, July 1998.
URL: https://ci.nii.ac.jp/naid/110003248457

マイクロ波帯移動通信の無線回線設計を目的として, 市街地における伝搬特性を把握するため, 1km程度の直線道路上で, 3.35GHz, 8.45GHz, 15.75GHzについて見通し内伝搬の瞬時変動特性の統計的性質を調べた.対数で表した相対受信電力の距離に対する短区間中央値について回帰曲線を求めると, 短区間中央値と回帰曲線の差は送信点から100m〜1000mの区間で定常的な性質を示し, 正規分布をする事が確かめられた.短区間標準偏差は, 送信点から100m〜1000mの区間で定常的な性質を示し, 安定成分が多く含まれると考えられる区間を除くと, 対数値が正規分布をした.さらに, 安定成分と変動成分の比について調べた結果, 十分遠方であっても安定成分が含まれる区間が多数存在する事が分かった.
Fading characteristics of microwave line-of-sight propagation in urban are measured and analyzed to make the feasibility study for future land mobile communication systems. Measurements have been made at 3.35, 8.45, and 15.75GHz along a 1-km flat and straight street in a Tokyo urban environment. Stationary was observed in the difference between the short-term medians and their regression curves ; and the differences are found normally distributed. Short-term standard deviation is also found stationary and follows logarithmic normal distribution by itself.

Hironari Masui, Koichi Takahashi, Kouzou Kage, Yoshihide Yamada, and Satoshi Takahashi, “Difference of path-loss characteristics due to reception antenna height in an urban LOS environment,” IEEE Antennas and Propagation Society International Symposium 1998 (AP-S/URSI), vol.3, pp.1672-1675, Atlanta, June 1998.

高橋 幸一, 増井 裕也, 高橋 賢, 鹿毛 豪藏, 小林 岳彦, “低アンテナ高の移動機に対する見通し内マイクロ波伝搬特性の測定および評価モデルの提案,” 電子情報通信学会技術研究報告, RCS98-39, June 1998.
Koichi Takahashi, Hironari Masui, Satoshi Takahashi, Kouzou Kage, and Takehiko Kobayashi, “Line-of-sight microwave propagation measurement with low antenna height and its new prediction model,” IEICE Technical Report, RCS98-39, June 1998.
URL: https://ci.nii.ac.jp/naid/110003305199

3.35GHz, 8.45GHzおよび15.75GHzのマイクロ波について, 低アンテナ高移動機の伝搬損距離特性の測定実験を行った.車載機を想定したアンテナ高(h_m=2.7m)および携帯機を想定したアンテナ高(h_m=1.6m)をそれぞれ受信局として使用した.携帯機の伝搬損距離特性の新たな評価方法として, 自由空間減衰係数より大きな値を距離減衰係数に用い, さらに距離の指数関数で表現される付加損失を加えた関数を用いて回帰分析を行った.その結果, 従来の方法よりも携帯機の実測値によく一致することを確認した.さらに提案式を用いて携帯機の実測値の解析を行った結果, 人の遮蔽の影響により送信アンテナ高依存性が大きくなることが分かった.
In this paper we discuss the path-loss model in street microcell environments and propose a new prediction model for the propagation loss in handy mode at the carrier frequencies of 3.35, 8.45, and 15.75 GHz, respectively. We used the measurement receiver in the vehicle-mount mode(h_m=2.7m)and the handy mode(h_m=1.6m), respectively. The propsed model is more suitable in the handy mode than the conventional model to predict the propagation loss from the measured data. The measured data analysis based on our proposed model shows that human bodies cause larger propagation loss and therefore the propagation loss depends more on the TX antenna height in the handy mode.

Satoshi Takahashi, Yoshihide Yamada, and Koji Ogura, “BER estimation with random phase technique applied to ray tracing,” The 48th IEEE Vehicular Technology Conference (VTC'98), vol.2, pp.855-859, Ottawa, May 1998.

増井 裕也, 高橋 幸一, 鹿毛 豪藏, 山田 吉英, 高橋 賢, “マイクロ波帯伝搬損失特性の測定,” 日本学術会議電波科学研究連絡委員会 第422回F分科会資料(URSI-F), March 1998.
Hironari Masui, Koichi Takahashi, Kouzou Kage, Yoshihide Yamada, and Satoshi Takahashi, “Measurement on microwave path loss characteristics,” The 422th URSI-F Document in Japan, March 1998.

高橋 賢, 山田 吉英, 小倉 浩嗣, 鹿毛 豪藏, 増井 裕也, 高橋 幸一, “多重波環境下でのアイ開口率の数値評価法,” 電子情報通信学会総合大会, B-5-25, March 1998. (電子情報通信学会学術奨励賞受賞論文)
Satoshi Takahashi, Yoshihide Yamada, Koji Ogura, Kouzou Kage, Hironari Masui, and Koichi Takahashi, “A numerical estimation method of eye aperture ratio in a multipath environment,” IEICE General Conference, B-5-25, March 1998. (This paper was received the IEICE Research Award)
URL: https://ci.nii.ac.jp/naid/110003266788

増井 裕也, 高橋 幸一, 鹿毛 豪藏, 山田 吉英, 高橋 賢, “マイクロセル内見通し伝搬における移動局アンテナ高の影響,” 電子情報通信学会総合大会, B-1-52, March 1998.
Hironari Masui, Kochi Takahashi, Kouzou Kage, Yoshihide Yamada, and Satoshi Takahashi, “An influence of reception antenna height on LOS path loss characteristics,” IEICE General Conference, B-1-52, March 1998.
URL: https://ci.nii.ac.jp/naid/110003266452

鹿毛 豪藏, 高橋 幸一, 増井 裕也, 高橋 賢, 山田 吉英, “見通し内伝搬の距離軸と時間軸で見た瞬時変動特性の差異,” 電子情報通信学会総合大会, B-1-37, March 1998.
Kouzou Kage, Koichi Takahashi, Hironari Masui, Satoshi Takahashi, and Yoshihide Yamada, “A difference in fast fading characteristics between distance and time axis in line-of-sight condition,” IEICE General Conference, B-1-37, March 1998.
URL: https://ci.nii.ac.jp/naid/110003266437

1997

Satoshi Takahashi, Kazumasa Taira, and Yoshihide Yamada, “Estimation of multimath propagation characteristics using ray tracing with random phase summation,” The Third Asia-Pacific Conference on Communications (APCC ‘97), pp.558-562, Sydney, Dec. 1997.

Satoshi Takahashi, “Radio propagation simulation method,” United States Patent, 5,689,812, Nov. 18, 1997.
URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5689812.PN.&OS=PN/5689812&RS=PN/5689812

Satoshi Takahashi, Kazumasa Taira, and Yoshihide Yamada, “BER estimation by ray tracing with random phase summation,” The Fourth International Workshop on Mobile Multimedia Communications (MoMuC ‘97), pp.522-525, Seoul, Oct. 1997.

鹿毛 豪藏, 増井 裕也, 高橋 幸一, 高橋 賢, 山田 吉英, “停止状態における移動通信伝搬波の統計的性質の測定,” 電子情報通信学会ソサイエティ大会, B-1-29, Sept. 1997.
Kouzou Kage, Hironari Masui, Koichi Takahashi, Satoshi Takahashi, and Yoshihide Yamada, “Statistical characteristics of propagation for mobile communication measured in a stationary condition,” IEICE Society Conference, B-1-29, Sept. 1997.
URL: https://ci.nii.ac.jp/naid/110003341574

マイクロ波を移動通信に適用し携帯で使用する場合、直進性が強いため、周囲の移動体による遮蔽等のため激しいフェージング変動を伴うことが予想される。本稿ではどの程度伝搬路途中の車両等移動体の影響を受けるのか実験的に調査したのでその結果を報告する。

高橋 幸一, 鹿毛 豪藏, 増井 裕也, 高橋 賢, 山田 吉英, “マイクロ波帯における見通し内伝搬の周波数特性の検討,” 電子情報通信学会ソサイエティ大会, B-1-28, Sept. 1997.
Koichi Takahashi, Kouzou Kage, Hironari Masui, Satoshi Takahashi, and Yoshihide Yamada, “A study on frequency dependence of microwave path loss in LOS condition,” IEICE Society Conference, B-1-28, Sept. 1997.
URL: https://ci.nii.ac.jp/naid/110003341573

電波伝搬の周波数特性は1.5GHz帯までが詳しく調べられている。この度、より高い周波数の実用を目指して伝搬実験を行い、伝搬損失算出式の周波数減衰係数を求めたので報告する。

高橋 賢, “アンテナ,” 特許公開平成9-232835, Sept. 5, 1997.

高橋 賢, 平 和昌, 山田 吉英, “ランダム位相合成レイトレース法を用いたビット誤り率の評価,” 電子情報通信学会技術研究報告, AP97-75, July 1997.
Satoshi Takahashi, Kazumasa Taira, and Yoshihide Yamada, “BER estimation by ray tracing with random phase summation,” IEICE Technical Report, AP97-75, July 1997.
URL: https://ci.nii.ac.jp/naid/110003247092

等価低域系による解析に, レイトレース法で得た伝搬路のインパルス応答を適用することで, ビット誤り率の評価を行うことができる. しかし, 1O^<-6>程度の誤り率を評価するときには1O^7個以上のランダム符号入力に対して誤りビット数を計測する必要があり, 多くの評価時間を必要とする. 短時間でビット誤り率を評価するため, 符号間隔内に到達した遅延波を希望波, それ以外の遅延波を不要波と分類し, それぞれの波がランダム位相を取るときのビット誤り率を特性関数法を用いて解析的に求めた. 不要波はその実振幅値が, また希望波は原点からの信号振幅が符号判定に寄与するとモデル化し, それぞれの確率密度関数を得る. 1O^<-6>程度の誤り率の評価であれば, 提案法を用いることにより短時間でビット誤り率の評価が可能である.
Bit error rate can be estimated by means of the equivalent base band analysis with the impulse responses obtained from ray tracing. However, at least random data of 10^7 are required to obtain the bit error rate of 1O^<-6> order, which requires a lot of evaluation time. In this paper, the bit error rate estimation method which can evaluate in a shorter time is presented. To achieve a quick estimation, the proposed method uses the characteristics function method to obtain the composite probability of desired waves and undesired waves. These waves are classified in terms of their delay time. More than 1O^<-6> of bit error rate can be estimated by means of the proposed method.

Satoshi Takahashi, Kazumasa Taira, and Yoshihide Yamada, “Radio zone designing by ray tracing with random phase summation” Teletraffic Modeling of Multimedia Mobile Communication Systems, pp.37-42, Niigata, March 1997.
URL: https://ci.nii.ac.jp/naid/10022291214

高橋 賢, “ランダム位相合成レイトレース法を応用した繰返しゾーン数の評価,” 電子情報通信学会総合大会, B-1-29, March 1997.
Satoshi Takahashi, “An estimation of the number of reuse cells by means of the ray trace method with the random phase summation,” IEICE General Conference, B-1-29, March 1997.
URL: https://ci.nii.ac.jp/naid/110003251113

セル設計は, 所望の空間に対しては高い場所率で電波を到達させ, その他の空間で干渉を与える確率は低く抑えるように行うことが望ましい. このような瞬時値のとる確率を与えて求めた振幅の距離特性をもとに, 繰返しゾーン数を求めたので報告する.

平 和昌, 高橋 賢, 関澤 信也, ウー 剛, 岩崎 憲, 長谷 良裕, “低基地局アンテナ高マイクロセルにおけるマイクロ波帯見通し内伝搬損特性,” 電子情報通信学会総合大会, B-1-21, March 1997.
Kazumasa Taira, Satoshi Takahashi, Shinya Sekizawa, Gang Wu, Ken Iwasaki, and Yoshihiro Hase, “Pathloss characteristics for line-of-sight microcellular mobile communications in microwave band,” IEICE General Conference, B-1-21, March 1997.
URL: https://ci.nii.ac.jp/naid/110003251105

マルチメディア化をめざした移動通信システムの検討が数多く進められている. それらの運用は, マイクロ波帯を用いてマイクロセルでサービスされることが現実的である. その際, 伝搬路による損失分の情報はセル設計に不可欠なものであるが, 簡便に得るためのデータはあまり紹介されていないのが現状である. 本稿では, マイクロ波帯を用いた見通し内マイクロセルにおける伝搬損の値を同一条件下の自由空間伝搬損と比較することで簡便化し, セル設計に役立てられるよう検討した.

1996

高橋 賢, “ランダム位相合成レイトレース法による多重波伝搬特性の評価,” 電子情報通信学会ソサイエティ大会, B-16, Sept. 1996.
Satoshi Takahashi, “An estimation of the multiple wave propagation characteristics by means of the ray trace method with the random phase summation,” IEICE Society Conference, B-16, Sept. 1996.
URL: https://ci.nii.ac.jp/naid/110003337161

レイトレース法の入力情報誤差による推定精度の劣化を軽減するため,評価点に到達するパスがランダム位相を持つとして電界強度の中央値を求めた.実測との比較により推定精度の改善を確認したので,また,提案法の応用で瞬時値の90%信頼区間を推定したので報告する.

高橋 賢, “三次元レイトレース法を用いた屋内電波伝搬シミュレーション,” 日本学術会議電波科学研究連絡委員会 第407回F分科会資料(URSI-F分科会), Sept. 1996.
Satoshi Takahashi, “Indoor radio propagation simulation by means of the three-dimensional ray trace method,” The 407th URSI-F Document in Japan, Sept. 1996.

高橋 賢, “移動無線通信システムおよび電力制御方法,” 特許公開平成8-167872, June 25, 1996.

1995

中野 博文, 高橋 賢, 吉浦 裕, 梅澤 正宏, 小松 秀秋, “基地局配置支援システム,” 電子情報通信学会ソサイエティ大会, B-8, Sept. 1995.
Hirofumi Nakano, Satoshi Takahashi, Hiroshi Yoshiura, Masahiro Umezawa, and Hideyuki Komatsu, “The base station placement assistance tool,” IEICE Society Conference, B-8, Sept. 1995.
URL: https://ci.nii.ac.jp/naid/110003342844

移動通信システムのマイクロセル化に伴い,セルカバレージの把握と共に,効率的な基地局配置の必要性が高まっている.屋内伝搬シミュレータと基地局自動配置システムを組合せた支援システムを開発した.本報告ではユーザインターフェース部を中心に述ベる.

高橋 賢, “電力制御方式,” 特許公開平成7-212303, Aug. 11, 1995.

William H. Scales, Leslie W. Pickering, Satoshi Takahashi, and Takashi Sakai, “Base station placement for in-buliding microcellular PCS,” The Second Asia-Pacific Conference on Communications (APCC ‘95), no.2, pp.559-563, Osaka, June 1995.

Satoshi Takahashi, Kazuhito Ishida, Hiroshi Yoshiura, and Arata Nakagoshi, “An evaluation point culling algorithm for radio propagation simulation based on the imaging method,” The Fifth Virginia Tech’s Symposium on Wireless Personal Communications, pp.13.1-13.11, Blacksburg, June 1995.

1994

高橋 賢, 石田 和人, 吉浦 裕, “イメージ法を用いた電波伝搬シミュレーションの高速化,” 電子情報通信学会技術研究報告, RCS94-125, Nov. 1994.
Satoshi Takahashi, Kazuhito Ishida, and Hiroshi Yoshiura, “Fast algorithm for radio propagation simulation baed on imaging method,” IEICE Technical Report, RCS94-125, Nov. 1994.
URL: https://ci.nii.ac.jp/naid/110003235488

レイトレース法を用いた構内無線伝搬シミュレータを作成した。レイトレース法は任意の形状の部屋に適用可能であるという利点を持つ反面,多くの計算時間を必要とすることが問題点である。計算時間を削減するため,反射波の計算において,最後のイメージ点とその反射物体との位置関係により反射波の存在する領域をあらかじめ求め,その領域内の評価点のみ計算を行う手法を考察した。本手法を従来のレイトレース法に付加することにより,2次反射まで考えたとき,計算時間を従来法のそれの約半分に削減することができた。さらに,バスの判定の方法を工夫することにより,計算時間を従来法のそれの1, 4〜1/7にすることができた。
Indoor radio propagation simulator based on ray trace method is developed.Ray trace method can be applied to any arbitrary room, while lots of computation time are required to calculate its intensity distribution.In order to reduce the computation time,we propose the algorithm contains following procedures:(1)solving the areas which have reflection rays using each relationship between the last imaging point and the reflection object,(2)calculating intensity of each evaluation point within the each area.By adding this procedures into conventional ray tracing method,the computation time is reduced by half compared with that of the conventional ray tracing method.Furthermore,the computation time can be reduced to 1/4 - 1/7 time compared with that of the conven tional ray tracing method.

1993

高橋 賢, 三輪 進, “荷重移動平均を用いたレーダクラッタの抑圧法,” 電子情報通信学会論文誌(B-II), vol.J76-B-II, no.2, pp.113-120, Feb. 1993. (English translation is available at Satoshi Takahashi and Susumu Miwa, “Suppression of radar clutter with a weighted moving average filter,” Electronics and Communications in Japan, part 1, vol.77, no.1, pp.57-65, Jan.1994.)
Satoshi Takahashi and Susumu Miwa, “A method of suppressing radar clutter with a weighted moving average filter,” IEICE Transactions on Communications (Japanese Ed.), vol.J76-B-II, no.2, pp.113-120, Feb. 1993. (English translation is available at Satoshi Takahashi and Susumu Miwa, “Suppression of radar clutter with a weighted moving average filter,” Electronics and Communications in Japan, part 1, vol.77, no.1, pp.57-65, Jan.1994.)
URL: http://search.ieice.org/bin/summary.php?id=j76-b2_2_113&category=B&lang=J&year=1993&abst=
2nd PDF

レーダ受信機にはターゲット以外の不要な物体からの反射波が混入する.このレーダクラッタを抑圧する手法は以前から提案されているが,それらの多くは単一パルス検出特性の改善を目的としたものであるため,パルス間変動によりしばしばターゲットが消失する.本論文では,レーダクラッタの抑圧法としてパルス積分後のデータに対し移動平均および荷重移動平均を適用することを提案する.まず,近年クラッタのモデルとして提案されているK-分布モデルを用いて,パルス積分数が無限のときの信号対クラッタ比を求める.次に,荷重移動平均化に用いる重みの求め方を示し,X-バンドレーダで観測したシークラッタに対してこの重みを用いて処理を行った結果を示す.この荷重移動平均化により移動平均化よりも更に信号対クラッタ比を改善することができる.多数のパルスによりパルス積分を行った本論文の例において,単にしきい値検出を行うよりも,しきい値検出を行う前に移動平均化を行うことにより4.2dB,更に荷重移動平均化を行うことにより5.OdB信号対クラッタ比を改善することができた.

1992

1991

高橋 賢, 三輪 進, “空間的相関を用いたレーダクラッタの一処理法,” 電子情報通信学会技術研究報告, SANE91-40, Oct. 1991.
Satoshi Takahashi and Susumu Miwa, “A method of processing radar clutter using spatial correlation property,” IEICE Technical Report, SANE91-40, Oct. 1991.

高橋 賢, 三輪 進, “K-分布モデルを用いたレーダクラッタの自己相関特性,” 電子情報通信学会秋季全国大会, B-90, Sept. 1991.
Satoshi Takahashi and Susumu Miwa, “Characteristics on autocorrelation properties of radar clutter with the K-distribution model,” IEICE Fall Conference, B-90, Sept. 1991.

高橋 賢, 三輪 進, “K-分布モデルを用いたグランドクラッタの解析例,” 電子情報通信学会春季全国大会, B-170, March 1991.
Satoshi Takahashi and Susumu Miwa, “An example of the analysis of ground clutter with the K-distribution model,” IEICE Spring Conference, B-170, March 1991.