Papers - YAMAZATO Takaya

Joint decoding scheme using bit-level correlation of experimentally observed data

K. Kobayashi, T. Yamazato, M. Katayama

Technical Report of IEICE, vol.MoMuC2009-2, pp.7-12   Vol. Vol.MoMuC2009-2   page： pp.7-12   2009.5

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Language：Japanese  

In wireless sensor networks, a large number of sensor nodes are densely deployed for a reliable sensing of physical phenomenon. Due to the high density in the sensing field, sensor observations are spatially correlated. In this paper, we focus on joint channel decoding schemes utilizing the correlation of sensor observations. Our proposed scheme makes use of a bit-level correlation property of data observed in the real environment. The performance of our approach is examined by simulations using sensing data from experiments in a real indoor environment.

Joint decoding scheme using bit-level correlation of experimentally observed data Reviewed

KOBAYASHI Kentaro, YAMAZATO Takaya, KATAYAMA Masaaki

IEICE technical report   Vol. 109 ( 22 ) page： 7 - 12   2009.4

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Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

In wireless sensor networks, a large number of sensor nodes are densely deployed for a reliable sensing of physical phenomenon. Due to the high density in the sensing field, sensor observations are spatially correlated. In this paper, we focus on joint channel decoding schemes utilizing the correlation of sensor observations. Our proposed scheme makes use of a bit-level correlation property of data observed in the real environment. The performance of our approach is examined by simulations using sensing data from experiments in a real indoor environment.

Bit and Power Allocation for Power-Line Communications under Nonwhite and Cyclostationary Noise Environment Reviewed

N. Sawada, T. Yamazato, M. Katayama

IEEE International Symposium on Power Line Communications and Its Applications     page： -   2009.4

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Language：English  

This manuscript discusses the adaptive OFDM system for narrow-band power-line communications with nonwhite and cyclostationary noise environment. The bit and power allocation algorithm is proposed with the considerations on the cyclostationarity of power-line noise. Numerical evaluation shows that the proposed method can improve the average BER performance under PLC noise environment.

B-20-42 ISOMAC based energy efficient TDMA-MAC protocol for Sensor Networks Reviewed

CHEN Hiroshi, YAMAZATO Takaya, KATAYAMA Masaaki

Proceedings of the IEICE General Conference   Vol. 2009 ( 2 )   2009.3

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Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

1つの既知反射面と2つの受信機によるUWB ToA位置推定 Reviewed

キエトリンスキ ザレスキ ヤン, 山里 敬也, 片山 正昭

電子情報通信学会技術研究報告. WBS, ワイドバンドシステム : IEICE technical report   Vol. 108 ( 474 ) page： 211 - 216   2009.3

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Publishing type：Research paper (scientific journal)   Publisher：一般社団法人電子情報通信学会  

UWBは近距離,特に室内での位置推定のための技術として注目を集めている.しかし,通常用いられるTime of Arrival(ToA)による位置推定では,送信機からの直接波が最低でも3つの異なる位置にある受信機で必要になる.一般に,そのような条件が必ず満たされる訳では無い.本稿では,2つの異なる位置にある受信機を用いたToAによる新しい位置推定手法について提案する.提案手法では,例えば天井や壁などの,ある1つの平面に関する情報が既知であると仮定することで位置推定を実現する.提案するアルゴリズムは,新たに作成したUWB伝搬シミュレーターによって評価する.

Phase Compensation for Narrowband Power-Line Communication Channels with Cyclic Time-Varying Features Reviewed

SUGIURA Yoshie, YAMAZATO Takaya, KATAYAMA Masaaki

IEICE technical report   Vol. 108 ( 473 ) page： 513 - 518   2009.3

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Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

Phase transfer functions of power-line channels often show sharp and periodic variation synchronous to the (double of) mains frequency. This is a result of impedance change of nonlinear devices connected to the power-lines. This manuscript proposes a phase estimation strategy for phase compensation at a receiver under such environment. In the proposed method, phase estimates are calculated using cyclic observation (average) of the channel characteristics. The numerical examples under periodic phase variation of the channel and cyclostationary noise, show that the receiver with the proposed phase estimation scheme outperforms that with the conventional phase estimation which uses average over the whole observation period without considering the periodic feature of the channel.

Influence of channel errors on a wireless-controlled rotary inverted pendulum Reviewed

KOHINATA Reo, YAMAZATO Takaya, KATAYAMA Masaaki

IEICE technical report   Vol. 108 ( 472 ) page： 167 - 172   2009.3

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Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper discusses the influence of channel features to the performance of a wireless-controlled system. As an example of the system, a rotary inverted pendulum that has wireless connections in its feedback loop between a controller and the controlled system. As for the wireless channels, both a random error model and a burst error model are employed and the effects of transmission rate and errors to the control quality are evaluated. As a result, it is confirmed that the system with transmission errors can keep the pendulum stable when data rate of the communication is enough high and error rate is below a certain level. In addition, it is clarified that that burst errors in wireless channels affect more when the control quality is kept by compensating errors with higher transmission rate.

Influence of channel errors on a wireless-controlled rotary inverted pendulum Reviewed

KOHINATA Reo, YAMAZATO Takaya, KATAYAMA Masaaki

IEICE technical report   Vol. 108 ( 474 ) page： 167 - 172   2009.3

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Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper discusses the influence of channel features to the performance of a wireless-controlled system. As an example of the system, a rotary inverted pendulum that has wireless connections in its feedback loop between a controller and the controlled system. As for the wireless channels, both a random error model and a burst error model are employed and the effects of transmission rate and errors to the control quality are evaluated. As a result, it is confirmed that the system with transmission errors can keep the pendulum stable when data rate of the communication is enough high and error rate is below a certain level. In addition, it is clarified that that burst errors in wireless channels affect more when the control quality is kept by compensating errors with higher transmission rate.

Influence of channel errors on a wireless-controlled rotary inverted pendulum Reviewed

KOHINATA Reo, YAMAZATO Takaya, KATAYAMA Masaaki

IEICE technical report   Vol. 108 ( 473 ) page： 167 - 172   2009.3

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Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper discusses the influence of channel features to the performance of a wireless-controlled system. As an example of the system, a rotary inverted pendulum that has wireless connections in its feedback loop between a controller and the controlled system. As for the wireless channels, both a random error model and a burst error model are employed and the effects of transmission rate and errors to the control quality are evaluated. As a result, it is confirmed that the system with transmission errors can keep the pendulum stable when data rate of the communication is enough high and error rate is below a certain level. In addition, it is clarified that that burst errors in wireless channels affect more when the control quality is kept by compensating errors with higher transmission rate.

Phase Compensation for Narrowband Power-Line Communication Channels with Cyclic Time-Varying Features Reviewed

SUGIURA Yoshie, YAMAZATO Takaya, KATAYAMA Masaaki

IEICE technical report   Vol. 108 ( 472 ) page： 513 - 518   2009.3

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Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

Phase transfer functions of power-line channels often show sharp and periodic variation synchronous to the (double of) mains frequency. This is a result of impedance change of nonlinear devices connected to the power-lines. This manuscript proposes a phase estimation strategy for phase compensation at a receiver under such environment. In the proposed method, phase estimates are calculated using cyclic observation (average) of the channel characteristics. The numerical examples under periodic phase variation of the channel and cyclostationary noise, show that the receiver with the proposed phase estimation scheme outperforms that with the conventional phase estimation which uses average over the whole observation period without considering the periodic feature of the channel.

Phase Compensation for Narrowband Power-Line Communication Channels with Cyclic Time-Varying Features Reviewed

SUGIURA Yoshie, YAMAZATO Takaya, KATAYAMA Masaaki

IEICE technical report   Vol. 108 ( 474 ) page： 513 - 518   2009.3

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Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

Phase transfer functions of power-line channels often show sharp and periodic variation synchronous to the (double of) mains frequency. This is a result of impedance change of nonlinear devices connected to the power-lines. This manuscript proposes a phase estimation strategy for phase compensation at a receiver under such environment. In the proposed method, phase estimates are calculated using cyclic observation (average) of the channel characteristics. The numerical examples under periodic phase variation of the channel and cyclostationary noise, show that the receiver with the proposed phase estimation scheme outperforms that with the conventional phase estimation which uses average over the whole observation period without considering the periodic feature of the channel.

Traffic Prediction Scheme for Resource Assignment of Satellite/Terrestrial Frequency Sharing Mobile Communication System Reviewed

AMAN Tomohiro, YAMAZATO Takaya, KATAYAMA Masaaki

IEICE technical report   Vol. 108 ( 440 ) page： 55 - 60   2009.2

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Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

Satellite/Terrestrial Frequency Sharing Mobile Communication System is drawing an attention for interpolation between satellite mobile communication and terrestrial mobile communication and improvement of spectrum utilization efficiency. Spectrum utilization efficiency can be improved in this system by sharing common frequency bands in satellite mobile and terrestrial mobile communication system and using dynamic resource assignment. But it is need to traffic prediction for dynamic resource assignment. This report propose traffic prediction method using neural network.

衛星／地上周波数共用移動通信システムに置ける資源割当てのためのトラヒック予測

阿萬友洋，山里敬也, 片山正昭

電子情報通信学会技術研究報告     page： -   2009.2

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Language：Japanese  

協力通信は複数の無線ノードが協力して同一の情報を送信することにより伝送距離を延長し，各ノードの消費電力を低減できる．本稿では，複数のクラスタに分割された無線センサネットワークに協力通信を適用することを考える．クラスタ間協力通信を行うには同一クラスタ内の複数のノードで情報を共有しなければならず，そのためにはクラスタヘッドに選出されたノードがクラスタ内に情報をブロードキャストする必要がある．しかし，このクラスタヘッドの選出手法によりネットワーク全体の消費電力が左右される．そこで，センサネットワークの稼働時間の延長を目的とし，各ノードの残余電力を考慮したクラスタヘッドの選出手法を提案する．結果より，提案手法はセンサノード稼働率，Outage確率共に改善可能であることを示す．

Cluster-based Cooperative Transmission considering the Residual Power of Wireless Sensor Nodes Reviewed

TAKESHIMA Koki, YAMAZATO Takaya, KATAYAMA Masaaki

IEICE technical report   Vol. 108 ( 399 ) page： 83 - 87   2009.1

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Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

Cooperative transmission can extend the transmission range by transmitting the same data from multiple wireless nodes, and consequently can reduce the consumed power of each node. In this paper, we apply the cooperative transmission to a wireless sensor network where the sensor nodes are organized into multiple clusters. To perform the cluster-based cooperative transmission, it has to choose a cluster head which broadcasts its decoded data to other nodes in a cluster. The overall dissipation power is, however, governed by the cluster head selection criterion. In this paper, we propose a simple cluster head selection criterion considering the residual power of each sensor node, and aim to extend the network lifetime. As results, the proposed scheme shows the best in the active sensor node rate and outage probability.

Turbo Equalization for Inter-Vehicle Communication Based on MC-CDMA Reviewed

HIRAIWA Noriaki, SAKATA Atsunori, YAMAZATO Takaya, KATAYAMA Masaaki

The IEICE transactions on communications B   Vol. 92 ( 1 ) page： 367 - 369   2009.1

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Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

Tracking an LED Array Using Optical Flow for Visible Light Communication System

H. Chinthaka N. Premachandra, T. Yendo, M. P. Tehrani, T. Yamazato, H. Okada, T. Fujii, M. Tanimoto

2009 ITE Winter Annual Convention     page： -   2009.1

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Language：Japanese  

We propose a visible light road-to-vehicle communication system at intersection as one of ITS technique. In this system, the communication between vehicle and an LED array is approached using LED array as a transmitter, and on-vehicle high-speed camera as a receiver. The LEDs in the transmitter are emitted in 500Hz and those emitting LEDs are captured by a high-speed camera for making communication. Here, the luminance value of LEDs in the transmitter should be captured in consecutive frames to achieve effective communication. For this purpose, first the transmitter should be identified, then it should be tracked in consecutive frames while the vehicle is moving, by processing the images from the high-speed camera. In this paper, we mainly introduce an algorithm to track the transmitter using optical flow and edge information.

Cluster-based Cooperative Transmission considering Residual Power of Wireless Sensor Nodes

K. Takeshima, T. Yamazato, M. Katayama

Technical Report of IEICE   Vol. USN2008-76   page： 83-87   2009.1

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Language：Japanese  

In this letter, we propose a new SC/MMSE Turbo equalizer for inter-vehicle communication based on MC-CDMA. We modify the MMSE filter in SC/MMSE Turbo equalizer focusing on the difference of channel transfer function of each car. As results, we show that better performance is obtained.

Turbo Equalization for Inter-Vehicle Communication based on MC-CDMA Reviewed

N. Hiraiwa, A. Sakata, T. Yamazato, M. Katayama

IEICE Transactions on Communications   Vol. J92-B ( 1 ) page： 367-369   2009.1

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Language：Japanese   Publishing type：Research paper (scientific journal)  

4-5 Tracking an LED Array Using Optical Flow for Visible Light Communication System Reviewed

PREMACHANDRA H. Chinthaka N., YENDO Tomohiro, Panahpour TEHRANI Mehrdad, YAMAZATO Takaya, OKADA Hiraku, FUJII Toshiaki, TANIMOTO Masayuki

PROCEEDINGS OF THE ITE WINTER ANNUAL CONVENTION   Vol. 2009 ( 0 ) page： _4-5-1_ - 5-1_   2009

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Institute of Image Information and Television Engineers  

We propose a visible light road-to-vehicle communication system at intersection as one of ITS technique. In this system, the communication between vehicle and an LED array is approached using LED array as a transmitter, and on-vehicle high-speed camera as a receiver. The LEDs in the transmitter are emitted in 500Hz and those emitting LEDs are captured by a high-speed camera for making communication. Here, the luminance value of LEDs in the transmitter should be captured in consecutive frames to achieve effective communication. For this purpose, first the transmitter should be identified, then it should be tracked in consecutive frames while the vehicle is moving, by processing the images from the high-speed camera. In this paper, we mainly introduce an algorithm to track the transmitter using optical flow and edge information.

DOI： 10.11485/itewac.2009.0__4-5-1_

CiNii Research

Channel Estimation and Tracking Schemes for the Pulse-Shaping OFDM Systems Reviewed

Mongol Bayarpurev, Yamazato Takaya, Katayama Masaaki

2009 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS, VOLS 1-8     page： 3076 - 3080   2009

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Publishing type：Research paper (scientific journal)  

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