研究者詳細 - 田野　哲

論文 - 田野　哲

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Experimental Verification of PER Performance of STBC-based Multi-hop Cooperative Relaying 査読

Makoto Miyagoshi, Hidekazu Murata, Susumu Yoshida, Koji Yamamoto, Daisuke Umehara, Satoshi Denno, Masahiro Morikura

2012 IEEE VEHICULAR TECHNOLOGY CONFERENCE (VTC FALL) 2012年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, the end-to-end packet error rate (PER) performance of a space-time block code (STBC) based multi-hop cooperative relaying system is discussed. This system consists of a source, a destination, and two STBC based cooperative relays in each hop. These relays decode their received packets and forward the packets only when no error is found. In this system, there are conditions where the end-to-end PER performance improves with the number of hops. The theoretical end-to-end PER performance of this system have been derived analytically. However, in real-world wireless systems, various practical issues, e. g., timing synchronization and imperfect channel estimation, have a large impact on the performance. To confirm the end-to-end PER performance of this system in actual setup, an in-lab experiment using a fading emulator and four transceivers is performed under Rayleigh fading environment. The experimental results clarify the PER performance of the STBC based multi-hop cooperative relaying system. In addition, the theoretical PER performance is also verified from the experimental results.

DOI： 10.1109/VTCFall.2012.6399343

A Reduced-Complexity Multiband MIMO Receiver with Estimation of Analog Devices Imperfection 査読

Tomoya Ohta, Masahiro Morikura, Satoshi Denno

2012 IEEE 75TH VEHICULAR TECHNOLOGY CONFERENCE (VTC SPRING) 2012年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Cognitive radios are of interest because they are capable of high frequency utilization efficiency. Multiband multiple-input multiple-output (MIMO) receivers based on heterodyne reception have been proposed for use in cognitive radios. This paper proposes a reduced-complexity multiband MIMO receiver that can achieve high performance by correcting the imperfection of the Hilbert transformer in the intermediate frequency (IF) band. However, the imperfection of the analog devices in the feedback loop causes poor performance. Therefore, a scheme for correcting the imperfection of the analog devices is proposed.

DOI： 10.1109/VETECS.2012.6239940

A Successive Detector with Virtual Channel Detection for Cooperative Multiuser MIMO Systems 査読

田野哲

Proceedings of the IEEE VTS Asia Pacific Wireless Communications symposium 1 1 - 5 2012年

仮想伝搬路判定を用いた逐次復号法のための演算量低減法

大西遼太, 田野哲, 梅原大祐, 守倉正博

電子情報通信学会論文誌. B, 通信 = The transactions of the Institute of Electronics, Information and Communication Engineers. B 94 ( 12 ) 1585 - 1594 2011年12月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

移動通信におけるダウンリンク高速化のため受信アンテナ数以上の空間多重化が可能な仮想伝搬路を適用した逐次復号法が提案されている.この方法は,最ゆう検出であるMLDに比較してはるかに少ない演算量で実装できるものの,ストリーム数の増大に伴い,指数関数的に演算量が増大するという問題がある.そこで,本論文ではこの演算量を低減するための効率的なフィルタ生成法及び信号検出法を提案する.送信ストリーム数がN_T,受信アンテナ数がN_RのシステムをN_T×N_Rと表すと,計算機シミュレーションの結果,提案法により,特性を劣化させることなく演算量を,E_b/N_0=10dBのとき,8×4のシステムで約20%,4×2のシステムで約40%にまで低減できることを示す.

A Virtual Layered Space-Frequency Receiver Architecture with Iterative Decoding 査読

Jun Imamura, Satoshi Denno, Daisuke Umehara, Masahiro Morikura

IEICE TRANSACTIONS ON COMMUNICATIONS E94B ( 7 ) 1994 - 2002 2011年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

In this paper, a novel receiver architecture is proposed for multiple-input-multiple-output (MIMO) systems; the proposed architecture helps achieve superior performance in multipath fading channels when the number of layered streams exceeds the number of receiving antennas. In this architecture, the concept of "virtual channel" is adopted to attain diversity gain even when successive detection is applied for reducing computational complexity, while orthogonal frequency division multiplexing (OFDM) is employed to combat multipath fading. Actually, successive detection is carried out in all possible virtual channels, and the virtual channel with the minimum error probability is detected with the assistance of the maximum a-posteriori (MAP) decoder in the architecture. In addition, soft input and soft output (SISO) iterative detection is introduced in the virtual channel estimation scheme. The performance of the proposed architecture is verified by computer simulations. This architecture can be implemented with lesser complexity than that in maximum likelihood detection (MLD), but the gain in the former case exceeds that in the latter by 4.5 dB at the BER of 10(-3) for 4 x 2 MIMO-OFDM.

DOI： 10.1587/transcom.E94.B.1994

Theoretical Performance Analysis of an Image-Band Interference Canceller with Deterministic Imbalance Estimation 査読

Satoshi Denno, Ke Liu, Tatsuo Furuno, Masahiro Morikura

IEICE TRANSACTIONS ON COMMUNICATIONS E94B ( 4 ) 968 - 977 2011年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

It is known that a heterodyne multimode receiver implemented with a single RF (Radio Frequency) receiver suffers from image-band interference due to imbalance, i.e. the phase error and the gain imbalance of the RF Hilbert transformer. The blind image band interference canceler with deterministic imbalance estimation that has been proposed mitigates the image-band interference. This performance of the image-band interference canceler is analyzed theoretically in this paper. As a result, it is revealed that estimation accuracy of the deterministic imbalance estimation is improved slightly as the imbalance becomes greater. In addition, it is also shown that the deterministic estimation achieves better performance as the power of image-band interference increases. The performance is confirmed by computer simulation.

DOI： 10.1587/transcom.E94.B.968

Performance analysis of slotted ALOHA and network coding for single-relay multi-user wireless networks 査読

Daisuke Umehara, Satoshi Denno, Masahiro Morikura, Takatoshi Sugiyama

AD HOC NETWORKS 9 ( 2 ) 164 - 179 2011年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

Deployment of wireless relay nodes can enhance system capacity, extend wireless service coverage, and reduce energy consumption in wireless networks. Network coding enables us to mix two or more packets into a single coded packet at relay nodes and improve performances in wireless relay networks. In this paper, we succeed in developing analytical models of the throughput and delay on slotted ALOHA (S-ALOHA) and S-ALOHA with network coding (S-ALOHA/NC) for single-relay multi-user wireless networks with bidirectional data flows. The analytical models involve effects of queue saturation and unsaturation at the relay node. The throughput and delay for each user node can be extracted from the total throughput and delay by using the analytical models. One can formulate various optimization problems on traffic control in order to maximize the throughput, minimize the delay, or achieve fairness of the throughput or the delay. In particular, we clarify that the total throughput is enhanced in the S-ALOHA/NC protocol on condition that the transmission probability at the relay node is set at the value on the boundary between queue saturation and unsaturation. Our analysis provides achievable regions in throughput on two directional data flows at the relay node for both the S-ALOHA and S-ALOHA/NC protocols. As a result, we show that the achievable region in throughput can be enhanced by using network coding and traffic control. (C) 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.adhoc.2010.07.005

マルチバンドMIMO-MMSE受信機の構成法とその劣化補償法

玉置真大, 田野哲, 古野辰男, 守倉正博

電子情報通信学会論文誌. B, 通信 = The transactions of the Institute of Electronics, Information and Communication Engineers. B 94 ( 2 ) 234 - 244 2011年2月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

任意の空き周波数でMIMO空間多重通信を行うコグニティブ無線のためのMIMO-MMSE受信機構成法を提案する.受信機構成は単一の周波数変換回路により実現できる可能性があるヘテロダイン受信方式を前提とする.ただし,イメージバンド干渉を緩和するためデュアル周波数変換法を適用する.更にハードウェア規模を低減するための手法を提案する.そして,提案した演算量低減法が高い伝送特性を達成するための条件を明らかにする.言い換えれば条件が満足されない場合には提案法は特性が劣化する.そこで,この劣化を補償する方法までも提案する.提案法がイメージ対所望信号電力費が-60dBでもイメージ干渉がない場合と同様の特性が達成されることを計算機シミュレーションにより示す.

簡易な信号処理を用いるセンサ協調型ビーム形成法の検討

中野淳次郎, 駒田善紀, 冨里繁, 田野哲, 秦正治

電子情報通信学会論文誌. B, 通信 = The transactions of the Institute of Electronics, Information and Communication Engineers. B 94 ( 2 ) 137 - 146 2011年2月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

本論文では,センサネットワークにおいてセンサ間の距離が大きい場合でも安定的な通信を実現することを目的として,複数のセンサが協調して適応的にビームを形成するセンサ協調型ビーム形成法を提案する.本ビーム形成法では,協調する送信センサにおいて受信センサからのパイロット信号の受信位相を反転させて送信位相を設定することにより,受信センサで同相合成を実現している.このため各送信センサでは簡易な信号処理で済むため,センサネットワークにおいてもビーム形成が可能となる.また,送信センサ間のキャリヤ同期の不完全性による位相誤差に対応するため,受信側でも協調する.このセンサ協調型ビーム形成法について伝送特性を評価した.更に,提案ビーム形成法における消費電力低減効果を明らかにした.シミュレーション評価により,送信センサ間の送信位相誤差が大きい場合においても提案手法が有効に動作し,センサ協調を行わない場合と比較して,80%以上の消費電力低減効果が得られることを示した.

A virtual layered space-frequency receiver for multiuser MIMO-OFDM systems 査読

田野哲

Proceedings of the IEEE 74th Vehicular Technology Conference 1 1 - 5 2011年

Experimental results of two-way channel estimation technique for coordinated multi-point transmission 査読

Hidekazu Murata, Koji Yamamoto, Susumu Yoshida, Satoshi Denno, Daisuke Umehara, Masahiro Morikura

ICICS 2011 - 8th International Conference on Information, Communications and Signal Processing 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

This paper presents an experimental setup of a multi-user MIMO linear precoding system. The experimental system consists of a base station with two antennas and two mobile stations. In this system, a two-way channel estimation technique is implemented in which mobile stations just send back the received signals along with their training sequences. In this technique, the base station can obtain the channel coefficients of both the uplink and the downlink. This two-way multiple-input multiple-output channel estimation technique has been proposed and mathematically analyzed in literature. Computer simulation results have been reported to identify the required hardware specifications for amplify and forward operation in mobile stations by examining the bit error rate performance. However, hardware implementation feasibility of this technique is not studied yet. In this paper, feasibility of a multi-user MIMO linear precoding system using two-way channel estimation technique is shown by in-lab experiments. © 2011 IEEE.

DOI： 10.1109/ICICS.2011.6173520

A Virtual Layered Space-Frequency Receiver for Multiuser MIMO-OFDM systems 査読

Akihito Taya, Satoshi Denno, Daisuke Umehara, Masahiro Morikura, Hidekazu Murata, Koji Yamamoto, Susumu Yoshida

2011 IEEE VEHICULAR TECHNOLOGY CONFERENCE (VTC FALL) 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, we propose a virtual layered space-frequency receiver with an ordered successive detector for multiuser multiple-input multiple-output (MU-MIMO) systems where multiple transmitters cooperate with one another. The proposed receiver enables high-speed transmission in the systems even if the transmitters know only partial channel state information (CSI). Actually, the receiver shows such superior performance when the concept of "virtual channel" is applied to cooperative MU-MIMO systems. Moreover, we propose an iterative detection scheme for the receiver; in this scheme, some signals from the Viterbi decoder are fed back to the ordered successive detector. The proposed iterative scheme helps improve the transmission speed when the number of cooperating transmitters is increased. We evaluate the performance of MIMO systems in which the transmitters have four antennas each and two users have two antennas. The receiver can double the transmission speed at the cost of 3 dB in E-b/N-0 at a BER of 10(-4). Furthermore, the receiver can triple the transmission speed at the cost of 7 dB in E-b/N-0 at a BER of 10(-4). When the system has three transmitters, we observe an error floor. However, the proposed iterative method can suppress the error to a value below BER = 10(-7).

Distributed transmit power control for distributed antenna systems using MRC 査読

Shigemasa Kumagawa, Koji Yamamoto, Hidekazu Murata, Susumu Yoshida, Daisuke Umehara, Satoshi Denno, Masahiro Morikura

ICICS 2011 - 8th International Conference on Information, Communications and Signal Processing 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Distributed antenna systems (DAS) are studied in order to improve the coverage area of wireless communication systems under transmit power constraint. In order to reduce the computational complexly among clusters, in DAS, it is imperative to control the inter-cluster interference in a decentralized way. In this paper, a distributed power control among clusters for single-user DAS based on Foschini-Miljanic's algorithm is proposed. The objective of the proposed algorithm is to mitigate the interference among clusters and satisfy the desired SINR at each mobile station (MS). In the algorithm, first signal power after MRC at MS in a cluster is calculated, then the transmit power of the BSAs in the corresponding cluster is updated according to the predefined transmit power ratio. In addition, the convergence condition is derived, and the performance of the proposed algorithm is evaluated through computer simulations. © 2011 IEEE.

DOI： 10.1109/ICICS.2011.6173525

A Virtual Layered Signal Processing Receiver for 16-QAM with Transmit Signal Rotation 査読

田野哲

Proceedings of 5th international conference on signal processing and communication systems 1 1 - 5 2011年

A Lattice-Reduction-Aided MIMO Receiver with Virtual Channel Detection 査読

田野哲

Proceedings of 5th international conference on signal processing and communication systems 1 1 - 5 2011年

Enhancement of CSMA/CA and Network Coding in Single-Relay Multi-User Wireless Networks 査読

HUANG Chun-Hsiang, UMEHARA Daisuke, DENNO Satoshi, MORIKURA Masahiro, SUGIYAMA Takatoshi

IEICE transactions on communications 93 ( 12 ) 3371 - 3380 2010年12月

記述言語：英語出版者・発行元：The Institute of Electronics, Information and Communication Engineers

Network coding is a promising technique for improving system performance in wireless multihop networks. In this paper, the throughput and fairness in single-relay multi-user wireless networks are evaluated. The carrier sense multiple access with collision avoidance (CSMA/CA) protocol and network coding are used in the medium access control (MAC) sublayer in such networks. The fairness of wireless medium access among stations (STAs), the access point (AP), and the relay station (RS) results in asymmetric bidirectional flows via the RS; as a result the wireless throughput decreases substantially. To overcome this problem, an autonomous optimization of minimum contention window size is developed for CSMA/CA and network coding to assign appropriate transmission opportunities to both the AP and RS. By optimizing the minimum contention window size according to the number of STAs, the wireless throughput in single-relay multi-user networks can be improved and the fairness between bidirectional flows via the RS can be achieved. Numerical analysis and computer simulations enable us to evaluate the performances of CSMA/CA and network coding in single-relay multi-user wireless networks.

DOI： 10.1587/transcom.E93.B.3371

その他リンク： https://jlc.jst.go.jp/DN/JALC/00359736964?from=CiNii

Enhancement of IEEE 802.11 and Network Coding for Single-Relay Multi-User Wireless Networks 査読

Daisuke Umehara, Chun-Hsiang Huang, Satoshi Denno, Masahiro Morikura, Takatoshi Sugiyama

2010 4TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS) 2010年12月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Network coding is a promising technique for improving system performance in wireless multihop networks. In this paper, the throughput and fairness in single-relay multiuser wireless networks are evaluated. The carrier sense multiple access with collision avoidance (CSMA/CA) protocol and network coding are used in the medium access control (MAC) sublayer in such networks. The fairness of wireless medium access among stations (STAs), the access point (AP), and the relay station (RS) results in asymmetric bidirectional flows via the RS; as a result the wireless throughput decreases substantially. To overcome this problem, an autonomous optimization of minimum contention window size is developed for CSMA/CA and network coding to assign appropriate transmission opportunities to both the AP and RS. By optimizing the minimum contention window size according to the number of STAs, the wireless throughput in single-relay multi-user networks can be improved and the fairness between bidirectional flows via the RS can be achieved. Numerical analysis and computer simulations enable us to evaluate the performances of CSMA/CA and network coding in single-relay multi-user wireless networks.

LBERアダプティブアレーによる干渉抑圧特性の解析

田野哲, 梅原大祐, 守倉正博

電子情報通信学会論文誌. B, 通信 = The transactions of the Institute of Electronics, Information and Communication Engineers. B 93 ( 9 ) 1249 - 1258 2010年9月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

受信アンテナ素子数以上のユーザが存在する場合には,誤り率最小化規範に基づく適応アルゴリズムを用いたアダプティブアレーはMMSEを用いたアダプティブアレーよりも優れた特性を示すことが知られている.ただし,非線形演算を伴う誤り率最小化アダプティブアレーの特性は理論的に解析することが困難であるため,計算機シミュレーションにより特性が明らかにされてきた.そこで,本論文では誤り率最小化規範に基づく適応アルゴリズムの一つであるLBER(Least Bit Error Rate)アルゴリズムを取り上げ,このアルゴリズムを用いたアダプティブアレーの特性を理論的に解析し,受信アンテナ素子数以上のユーザが存在する場合の干渉抑圧メカニズムを明らかにする.

イメージ干渉と同一チャネル干渉を同時に抑圧する適応マルチバンドアレー

玉置真大, 田野哲, 古野辰男, 守倉正博

電子情報通信学会論文誌. B, 通信 = The transactions of the Institute of Electronics, Information and Communication Engineers. B 93 ( 2 ) 269 - 277 2010年2月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

干渉の抑圧にアレーアンテナが効果的であるが,受信機の構成を複雑にする.更に現在,無線端末の機能向上のため多様な送受信機が端末に搭載され,構成をより複雑にしている.端末を小型・軽量化するにはこれらの送受信機能が単一のRF回路で構成されることが望ましい.本論文ではこれら複数の送受信機能を単一のRF回路で実現可能かつ,アダプティブアレーの機能をも具備したマルチバンドアレーの構成を提案する.更に演算量を低減するための係数変換法も提案する.提案法受信機により強い干渉とヒルベルト変換加器の誤差による残留イメージ干渉を同時に抑圧できる事を計算機シミュレーションにより明らかにした.

Throughput Analysis of Two-Hop Wireless CSMA Network Coding 査読

Daisuke Umehara, Satoshi Denno, Masahiro Morikura, Takatoshi Sugiyama

2010 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS 2010年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper considers two-hop wireless systems employing network coding and a carrier sense multiple access (CSMA) protocol. Network coding is a recent and highly regarded technology for the capacity enhancement of multiple unicast and multisource multicast networks. The two-hop wireless CSMA systems are often involved with the hidden node problem, but the impact of the hidden nodes on network coding has not been analyzed in theory. This paper provides explicit expressions of the throughput for single-relay two-hop wireless CSMA systems both without and with network coding. The throughput can be obtained from these expressions for given system parameters even when end nodes via the relay node are hidden each other. Furthermore it is shown that the transmit probability of the relay node is a design parameter that is crucial for maximizing the achievable throughput for CSMA systems with network coding. It is clarified that the throughput for CSMA systems can be enhanced as compared with that for slotted ALOHA systems in case of non-hidden end nodes whereas it deteriorates considerably in case of hidden end nodes.

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