研究者詳細 - 田野　哲

Genetic Algorithm Based Channel Pattern Selection for Spatial Modulation Using Slots of Leaky Coaxial Cable 査読

その他リンク： https://dblp.uni-trier.de/db/conf/wpmc/wpmc2022.html#DennoFH22

Kenta Nagayama, Erika Kouda, Junjin Zhu, Yafei Hou, Satoshi Denno

the 25th International Symposium on Wireless Personal Multimedia Communications (WPMC 2022) 221 - 225 2022年11月

Adaptive Resource Allocation Based on Factor Graphs in Non-Orthogonal Multiple Access 査読

Taichi YAMAGAMI, Satoshi DENNO, Yafei HOU

IEICE Transactions on Communications E105.B ( 10 ) 1258 - 1267 2022年10月

A Non-Linear Distortion Noise Canceller for Pre-Distortion Characteristic Error Compensation in LED Visible Light Communications 査読

Norihiro Tokui, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

the 2022 IEEE 10th Globa; Conference on Consumer Electronics (GCCE 2022) 198 - 201 2022年10月

A Low Complexity Non-linear Iterative Receiver for Overloaded MIMO-OFDM Systems 査読

Shuhei Makabe, Satoshi Denno, Yafei Hou

the 2022 27th Asia Pacific Conference on Communications (APCC2022) 488 - 493 2022年10月

Asynchronous Periodic Interference Signals Cancellation in Frequency Domain 査読

Satoshi DENNO, Yafei HOU

IEICE Transactions on Communications E105.B ( 9 ) 1087 - 1096 2022年9月

Particle Filter-Based Indoor Localization and Tracking Method Using Leaky Coaxial Cables 査読

Junjie Zhu, Kenta Nagayama, Erika Kouda, Yafei Hou, Satoshi Denno

2022 IEEE 33rd Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'22) 856 - 861 2022年9月

Low Complexity Soft Decoding With Superposition of Hard Decision Vectors in Lattice Reduction-Aided Linear Receivers 査読

Satoshi Denno, Koki Kashihara, Yafei Hou

2022 IEEE 33rd Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'22) 271 - 275 2022年9月

担当区分：筆頭著者,　責任著者記述言語：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

DOI： 10.1109/PIMRC54779.2022.9977505

Receivable signal sequence number increase in LED visible light wireless communications by spatially parallel signal transmission 査読

その他リンク： https://dblp.uni-trier.de/db/conf/pimrc/pimrc2022.html#DennoKH22

Ryosuke Okamoto, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

IEICE Communications Express 11 ( 6 ) 296 - 301 2022年6月

Evaluation of sensor terminal signal separation performance based on modulation systems in storage-based batch signal processing using STFT 査読

Takuyuki Hirakawa, Toru Nishiyama, Syo Nakaie, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

IEICE Communications Express 11 ( 6 ) 319 - 323 2022年6月

Periodic Interference Cancellation With Drift Estimation Based on Super-Resolution Techniques in Frequency Domain 査読

Satoshi Denno, Yafei Hou

2022 IEEE 95th Vehicular Technology Conference: (VTC2022-Spring) 1 - 5 2022年6月

Maximum Doppler Frequency Detection Based on Likelihood Estimation With Theoretical Thresholds 査読

Satoshi DENNO, Kazuma HOTTA, Yafei HOU

IEICE Transactions on Communications E105.B ( 5 ) 657 - 664 2022年5月

A Proposal of Spatial Modulation Using On/Off the Slots of Leaky Coaxial Cable 査読

Kenta Nagayama, Junjie Zhu, Pengcheng Hou, Yafei Hou, Satoshi Denno

2022 IEEE 4th Global Conference on Life Sciences and Technologies (LifeTech) 1 - 5 2022年3月

担当区分：最終著者記述言語：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

DOI： 10.1109/LifeTech53646.2022.9754939

Two-dimensional RSSI-Based Indoor Localization Using Multiple Leaky Coaxial Cables with a Probabilistic Neural Network 査読

その他リンク： https://dblp.uni-trier.de/db/conf/lifetech/lifetech2022.html#NagayamaZHHD22

Junjie Zhu, Pengcheng Hou, Kenta Nagayama, Yafei Hou, Satoshi Denno, Rian Ferdian

IEEE Access 10 21109 - 21119 2022年

Prediction Evaluation for RSSI Data Generated from Leaky Coaxial Cables over Indoor Environment. 査読

Pengcheng Hou, Junjie Zhu, Kenta Nagayama, Yafei Hou, Satoshi Denno

ICCE 1 - 5 2022年

Indoor Simultaneous TOA Estimation of Multiple Users Using Leaky Coaxial Cable. 査読

Junjie Zhu, Erika Kouda, Pengcheng Hou, Kenta Nagayama, Yafei Hou, Satoshi Denno

LifeTech 297 - 298 2022年

Adaptive Resource Allocation Based on Factor Graphs in Non-Orthogonal Multiple Access 査読

Taichi Yamagami, Satoshi Denno, Yafei Hou

The 24th International Symposium on Wireless Personal Multimedia Communications (WPMC 2021) 1 - 5 2021年12月

担当区分：責任著者記述言語：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 non-orthogonal multiple access with adaptive resource allocation based on factor graphs. The proposed non-orthogonal multiple access assigns multiple frequency resources for each device to send their packet. Even if the number of the devices is more than the frequency resources, the proposed non-orthogonal access allows all the devices to transmit their packets simultaneously for high capacity massive machine type communication (mMTC). Furthermore, this paper proposes adaptive resource allocation based on factor graphs that adaptively allocates the frequency resources to the devices for improvement of the transmission performances. This paper proposes two allocation criteria for the proposed adaptive allocation. This paper shows that the proposed non-orthogonal multiple access achieves superior transmission performance in 4-path Rayleigh fading channel with overloading ratio of 1.5, even without the adaptive resource allocation. The adaptive resource allocation enables the proposed non-orthogonal access to attain a gain of about 5 dB at the BER of 10(-4).

DOI： 10.1109/WPMC52694.2021.9700454

User Mobility Estimation Through Maximum Doppler Frequency Detection 査読

Satoshi Denno, Kazuma Hotta, Yafei Hou

2021 15th International Conference on Signal Processing and Communication Systems (ICSPCS2021) 1 - 5 2021年12月

担当区分：筆頭著者,　責任著者記述言語：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

DOI： 10.1109/ICSPCS53099.2021.9660311

A Compensation Method for Both Amplitude Deviation of Frequency Response and Non-Linear Distortion in LED Visible Light Wireless Communications 査読

その他リンク： https://dblp.uni-trier.de/db/conf/icspcs/icspcs2021.html#DennoHH21

Receivable Signal Sequence Number Increase by Spatially Parallel Signal Transmission in LED Visible Light Wireless Communications 査読

Ryosuke Okamoto, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

The 2021 IEICE 2nd International Conference on Emerging Technologies for Communications (ICETC) 1 - 5 2021年12月

Takeru Fukuyama, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

2021 20th International Symposium on Communications and Information Technologies (ISCIT) 114 - 117 2021年10月

Cyclic path switching for lattice reduction-aided iterative linear receivers in overloaded MIMO systems 査読

Satoshi Denno, Takuya Fujiwara, Yafei Hou

IEICE Communications Express 10 ( 10 ) 810 - 815 2021年10月

Eigenvalue Based Relay Selection for XOR-Physical Layer Network Coding in Bi-Directional Wireless Relaying Networks 査読

Satoshi DENNO, Kazuma YAMAMOTO, Yafei HOU

IEICE Transactions on Communications E104.B ( 10 ) 1336 - 1344 2021年10月

Examination of signal separation/demodulation method of multi-value modulation sensor terminal signal using STFT in storage batch signal processing 査読

Toru Nishiyama, Takuyuki Hirakawa, Syo Nakaie, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

IEICE Communications Express 10 ( 8 ) 458 - 462 2021年8月

Out-of-Bound Signal Demapping for Lattice Reduction-Aided Iterative Linear Receivers in Overloaded MIMO Systems 査読

Takuya FUJIWARA, Satoshi DENNO, Yafei HOU

IEICE Transactions on Communications E104.B ( 8 ) 974 - 982 2021年8月

Busy/Idle Duration Prediction for Video and Audio WLAN Traffics Using Autoregressive Predictor with Data Categorization 査読

Yafei Hou, Shun Kawasaki, Satoshi Denno

2021 23rd International Conference on Advanced Communication Technology (ICACT) 259 - 264 2021年2月

Busy/Idle Duration Models of Video and Audio WLAN Traffics and Their Prediction Performance. 査読

Yafei Hou, Shun Kawasaki, Satoshi Denno

The 23rd international conference on advanced communications technology (ICACT) 202 - 203 2021年2月

A Study of Throughput Prediction using Convolutional Neural Network over Factory Environment 査読

Yafei Hou, Kazuto Yano, Norisato Suga, Julian Webber, Eiji Nii, Toshihide Higashimori, Satoshi Denno, Yoshinori Suzuki

The 23rd international conference on adavanced communications technology (ICACT) 1 - 5 2021年2月

Frequency Domain Iterative Cancellation of Periodic Noise 査読

Yuya Furutani, Satoshi Denno, Yafei Hou

2020 International Symposium on Antennas and Propagation (ISAP) 1 - 2 2021年1月

Capacity Loss From Localization Error in MIMO Channel Using Leaky Coaxial Cable. 査読

Junjie Zhu, Yafei Hou, Kenta Nagayama, Satoshi Denno

IEEE Access 9 15929 - 15938 2021年

Modeling and Predictability Analysis on Channel Spectrum Status Over Heavy Wireless LAN Traffic Environment. 査読

Yafei Hou, Julian Webber, Kazuto Yano, Shun Kawasaki, Satoshi Denno, Yoshinori Suzuki

IEEE Access 9 85795 - 85812 2021年

Precoded Physical Layer Network Coding with Coded Modulation in MIMO-OFDM Bi-Directional Wireless Relay Systems. 査読

Satoshi Denno, Kazuma Yamamoto, Yafei Hou

IEICE Trans. Commun. 104-B ( 1 ) 99 - 108 2021年

Non-Orthogonal Packet Access Based on Low Density Signature With Phase Only Adaptive Precoding. 査読

Satoshi Denno, Ryoko Sasaki, Yafei Hou

IEICE Trans. Commun. 104-B ( 3 ) 328 - 337 2021年

Low-Complexity Implementation of Channel Estimation for ESPAR-OFDM Receiver. 査読

Yafei Hou, Rian Ferdian, Satoshi Denno, Minoru Okada

IEEE Trans. Broadcast. 67 ( 1 ) 238 - 252 2021年

Multi-Input Physical Layer Network Coding In Wireless Two-Way Relay Networks. 査読

Hideaki Tsugita, Satoshi Denno, Yafei Hou

17th IEEE VTC Asia Pacific Wireless Communications Symposium (IEEE VTS APWCS 2021), 1 - 5 2021年

Partial Perturbation to Alleviate the Performance Degradation of Vector Perturbation With Inaccurate Power Scaling Factors. 査読

Yafei Hou, Satoshi Denno

IEEE Trans. Broadcast. 67 ( 1 ) 324 - 336 2021年

Indoor Localization Using Leaky Coaxial Cable over a Multipath-rich Linear Cell Environment. 査読

Junjie Zhu, Kenta Nagayama, Yafei Hou, Satoshi Denno

IEEE 3rd global conference on life science and technologies, 280 - 281 2021年

RSSI-Based Indoor Localization Using Leaky Coaxial Cable with a PNN Approach. 査読

Junjie Zhu, Pengcheng Hou, Kenta Nagayama, Yafei Hou, Satoshi Denno

The 2021 IEEE 10th Globa; Conference on Consumer Electronics (GCCE 2021) 220 - 221 2021年

A Study of Throughput Prediction using Convolutional Neural Network over Factory Environment.

Yafei Hou, Kazuto Yano, Norisato Suga, Julian L. Webber, Eiji Nii, Toshihide Higashimori, Satoshi Denno, Yoshinori Suzuki

23rd International Conference on Advanced Communication Technology(ICACT) 429 - 434 2021年

Busy/Idle Duration Prediction for Video and Audio WLAN Traffics Using Autoregressive Predictor with Data Categorization.

Yafei Hou, Shun Kawasaki, Satoshi Denno

23rd International Conference on Advanced Communication Technology(ICACT) 259 - 264 2021年

Channel Status Prediction using Auto-regressive and Auto-regressive Integrated Predictors over WLAN Channel 査読

Yafei Hou, Naoya Hokimoto, Satoshi Denno

International Journal of Computer & Software Engineering 5 ( 2 ) 2020年12月

Transmission performance of a digital pre-distortion method followed by adaptive compander for LED visible light communications 査読

Saroma Era, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

the 2020 IEICE 1st International Confernce on Emerging Technologies for Communications (ICETC) 1 - 5 2020年12月

A study on window function and window width of STFT in collision signal separation and demodulation method using stored batch signal processing 査読

田野哲

IEICE Communications Express X10-B 1 - 5 2020年12月

Transmission performance of highly efficient modulation by collaborative linearization processing in both transmitter and receiver for LED visible light communications 査読

Keitaro Hirai, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

the 2020 IEICE 1st International Confernce on Emerging Technologies for Communications (ICETC) 1 - 5 2020年12月

A Flexible Overloaded MIMO Receiver with Adaptive Selection of Extended Rotation Matrices 査読

Satoshi DENNO, Akihiro KITAMOTO, Ryosuke SAWADA

IEICE Transactions on Communications E103.B ( 7 ) 787 - 795 2020年7月

Bit Stream Decorrelation in An Iterative Overloaded MIMO Receiver for Higher-Order QAMs. 査読

Takuya Fujiwara, Satoshi Denno, Yafei Hou

the 23th International Symposium on Wireless Personal Multimedia Communications (WPMC 2020) 1 - 5 2020年

Low Complexity Soft Input Decoding in an Iterative Linear Receiver for Overloaded MIMO. 査読

Satoshi Denno, Tsubasa Inoue, Yuta Kawaguchi, Takuya Fujiwara, Yafei Hou

IEICE Trans. Commun. 103-B ( 5 ) 600 - 608 2020年

Low Complexity Soft Decoding For Physical Layer Network Coding With Coded Modulation. 査読

Satoshi Denno, Tomoya Tanikawa, Hideaki Tsugita, Yafei Hou

2020 14th International Conference on Signal Processing and Communication Systems (ICSPCS2020) 1 - 5 2020年

担当区分：筆頭著者,　責任著者記述言語：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

DOI： 10.1109/ICSPCS50536.2020.9310008

Two Dimensional Indoor Localization with Multiple Leaky Coaxial Cables. 査読

その他リンク： https://dblp.uni-trier.de/db/conf/icspcs/icspcs2020.html#DennoTTH20

Junjie Zhu, Pengcheng Hou, Yafei Hou, Satoshi Denno, Minoru Okada

The 2020 IEEE 7th Global Conference on Consumer Electronics (GCCE) 626 - 627 2020年

A study for 2-D indoor localization using multiple leaky coaxial cables 査読

Junjie Zhu, Pengcheng Hou, Yafei Hou, Satoshi Denno, Minoru Okada

APSIPA TRANSACTIONS ON SIGNAL AND INFORMATION PROCESSING 9 2020年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CAMBRIDGE UNIV PRESS

Indoor localization technology, which can provide the location information of the target object or stochastic things, is becoming essential requirement for many applications and services such as Internet-of-Things (IoT), real-time control in the development of Fifth-generation (5G) technology. Leaky coaxial cable which can be used as antennas is able to detect the location of the user in a simple way due to its potential property. In this paper, we proposes a simple method to improve the localization accuracy of 2-D indoor localization using multiple LCX cables. In addition, we also evaluate the channel capacity loss due to the localization error of the LCX-MIMO using our proposed method.

DOI： 10.1017/ATSIP.2020.18

LED Lighting Arrangement for Spatially Parallel Signal Transmission in Visible Light Communication. 査読

Yusuke Kamei, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

the 2019 IEEE 7th Global Conference on Consumer Electronics (GCCE) 1123 - 1126 2019年10月

A Study of Capacity Loss from Localization Error in MIMO Channel Using Leaky Coaxial Cable. 査読

Junjie Zhu, Yafei Hou, Satoshi Denno, Minoru Okada

The 2019 IEEE 7th Global Conference on Consumer Electronics (GCCE), 1002 - 1003 2019年10月

Iterative Soft Input Decoding with Assistance of Lattice Reduction for Overloaded MIMO. 査読

Satoshi Denno, Tsubasa Inoue, Takuya Fujiwara, Yafei Hou

The IEEE 90th Vehicular Technology Conference (VTC2019-fall) 1 - 5 2019年9月

周期性干渉除去のための適応サイドバンド選択法査読

木村祐也, 田野哲, 侯亜飛

電子情報通信学会論文誌 J102-B ( 8 ) 595 - 604 2019年8月

担当区分：責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）

広帯域な周期性干渉信号による無線システムの特性劣化を補償する周期性干渉補償器のための適応サイドバンド選択法を提案する．提案法は所望変調信号以外の周波数帯すなわちサイドバンドを適応的に選択し，このサイドバンドの信号を用いて線形干渉の原理に基づき所望信号のSINR（Signal to Interference and Noise power Ratio）を改善する．本論文では，この適応選択のためのアルゴリズムを提案する．提案法は所望変調信号に加えて，複数の変調信号が同時に受信される現実的なモデルにおいても，高い干渉抑圧能力を有する．この特性を理論解析によって示すとともに，計算機シミュレーションにより評価する．所望の変調信号帯におけるCIR (Carrier to Interference power Ratio)が0dB，CNR (Carrier to Noise power Ratio)が30dBの環境で，ランダムにサイドバンドを選択した場合と比較し約26dBの特性改善が得られることを示す．また，提案法は理論的な上界を達成する選択法とほぼ同等の特性を達成しつつ，演算量は1/100程度で実現できることも示す．

DOI： 10.14923/transcomj.2018wfp0011

Low Density Signature Based Packet Access with Phase Only Adaptive Precoding. 査読

Optical Radio Channel Propagation in Wireless Communication Systems with LEDs 査読

Satoshi Denno, Shunsuke Fujitaka, Yafei Hou, Shigeru Tomisato, Kazuhiro Uehara

The 12th Global Symposium on Millimeter Waves (GSMM) 1 - 5 2019年5月

Near Optimum User Selection for Minimum Mean Square Error Based Tomlinson Harashima Precoding 査読

Satoshi Denno, Tomoyuki Baba, Kenta Asaka, Yafei Hou

International Journal of Computer & Software Engineering 4 ( 1 ) 2019年1月

自己回帰法を用いたWLANトラヒックとその予測性能のためのバス/アイドル持続時間モデル【JST・京大機械翻訳】

Hou Yafei, Tanaka Yusuke, Webber Julian, Yano Kazuto, Denno Satoshi, Kumagai Tomoaki

IEEE Conference Proceedings 2018-November ( APMC ) 893 - 895 2019年1月

Satoshi Denno, Ryoko Sasaki, Yafei Hou

The IEEE 89th Vehicular Technology Conference (VTC2019)-Spring 1 - 5 2019年

Coded Quadrature Amplitude Modulations For XOR Physical Layer Network Coding With Precoding. 査読

Satoshi Denno, Kazuma Yamamoto, Yafei Hou

The 22nd International Symposium on Wireless Personal Multimedia Communications (WPMC 2019) 1 - 6 2019年

担当区分：筆頭著者,　責任著者記述言語：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

DOI： 10.1109/WPMC48795.2019.9096064

XOR Physical Layer Network Coding with Non-Linear Precoding for Quadrature Amplitude Modulations in Bi-Directional MIMO Relay Systems. 査読

その他リンク： https://dblp.uni-trier.de/db/conf/wpmc/wpmc2019.html#DennoYH19

Satoshi Denno, Yuto Nagai, Yafei Hou

IEICE Trans. Commun. 102-B ( 10 ) 2073 - 2081 2019年

A Novel Low Complexity Lattice Reduction-Aided Iterative Receiver for Overloaded MIMO. 査読

Satoshi Denno, Yuta Kawaguchi, Tsubasa Inoue, Yafei Hou

IEICE Trans. Commun. 102-B ( 5 ) 1045 - 1054 2019年

Capacity of 4-by-4 MIMO Channel Using One Composite Leaky Coaxial Cable With User Position Information. 査読

Yafei Hou, Junjie Zhu, Satoshi Denno, Minoru Okada

IEEE Trans. Veh. Technol. 68 ( 11 ) 11042 - 11051 2019年

Relay Selection for Bi-directional Relay Systems with XOR-Phisical Layer Network Coding. 査読

Kazuma Yamamoto, Satoshi Denno, Yafei Hou

the 1The IEEE VTS Asia Pacific Wireless Communications symposium (IEEE VTS APWCS 2019) 1 - 5 2019年

狭帯域無線システムのための適応周期性干渉除去査読

佐藤雄一朗, 田野哲, 軽部俊和

電子情報通信学会論文誌 B J101-B ( 8 ) 627 - 636 2018年8月

担当区分：責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）

本論文では，インバータ等から放射される不要電磁波に起因する周期性干渉信号による狭帯域無線システムの特性劣化を軽減する適応干渉除去法を提案する．提案法では周波数領域における適応信号処理により，狭帯域無線システムに混入している周期性干渉信号を除去する．周期性雑音の位相雑音は周波数領域では大きな位相回転を引き起こし，干渉除去特性を劣化させるため，本論文では位相雑音の推定法も提案する．更に，位相雑音の演算量低減法も提案する．提案法の特性を計算機シミュレーションにより評価し，搬送波対雑音電力比が20dB，干渉電力対雑音電力比が0dBの環境で，約25dBの利得が得られることを示す．

DOI： 10.14923/transcomj.2018JBP3002

Uplink Multiuser MIMO Access with Probe Packets in Distributed Wireless Networks. 査読

Satoshi Denno, Yusuke Murakami

IEICE Trans. Commun. 101-B ( 6 ) 1443 - 1452 2018年6月

Performance Analysis of Low Complexity Lattice Reduction-Aided Iterative Receiver for Overloaded MIMO. 査読

Satoshi Denno, Yuta Kawaguchi, Tsubasa Inoue, Yafei Hou

The 12 International Conference on Signal Processing and Communication Systems (ICSPCS 2018), 1 - 5 2018年

担当区分：筆頭著者,　責任著者記述言語：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

DOI： 10.1109/ICSPCS.2018.8631747

Doppler Frequency Estimation using Overlap Frequency Domain Equalization. 査読

その他リンク： https://dblp.uni-trier.de/db/conf/icspcs/icspcs2018.html#DennoKIH18

Kohei Hashimoto, Satoshi Denno, Kazuoki Ichikawa, Takashi Okada, Yuji Aburakawa

The 21st International Conference on Wireless Personal Multimedia Communications (WPMC2018), 256 - 261 2018年

[Invited Paper] Adaptive Configuration of Forward Channels for Terminal Collaborative Reception 招待査読

Satoshi Denno, Daisuke Umehara

ITE Transactions on Media Technology and Applications 6 ( 1 ) 82 - 90 2018年

Low-complexity Power Allocation with Positional Information for 4-by-4 MIMO Channel using One Composite Leaky Coaxial Cable 査読

Junjie Zhu, Yafei Hou, Satoshi Denno, Minoru Okada

2018 IEEE 7TH GLOBAL CONFERENCE ON CONSUMER ELECTRONICS (GCCE 2018) 841 - 842 2018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

Leaky coaxial (LCX) cable can be used as antenna for wireless communication system and wireless power transfer which can be widely applied for many application scenarios including wireless service for IoT, automated factory using a large number of wireless devices. We have designed that one LCX cable can be used as two antennas which can releases the space requirement of MIMO deployment for wireless application. In this paper, we will further evaluate the 4-by-4 LCX-MIMO channel using one composite cable with two LCX cables. In addition, we also propose a low-complexity power allocation method for the LCX-MIMO system with the user's positional information (PI). The results show that the capacity is promising when the spacing between LCX cables is small as to 2cm. In addition, our proposed low-complexity power allocation has better capacity than that of using equal power allocation when SNR value is over the low range.

Adaptive forward link formation for terminal collaborative reception. 査読

Satoshi Denno, Hidekazu Murata, Daisuke Umehara

The 20th International Symposium on Wireless Personal Multimedia Communications (WPMC 2017) 292 - 296 2017年12月

フィードバック情報量低減を可能にする基地局協調システムのための線形プリコーディング査読

田野哲, 田谷昭仁, 村田英一, 梅原大祐, 山本高至, 吉田進, 守倉正博

電子情報通信学会論文誌 B J100-B ( 3 ) 270 - 279 2017年3月

New MU-MIMO random access employing THP with correlation based user scheduling. 査読

Tomoyuki Baba, Satoshi Denno

The 14th IEEE VTS Asia Pacific Wireless Communications symposium (IEEE VTS APWCS 2017) 1 - 5 2017年

Transmission quality improvement by LED back-off optimization for visible light wireless communications. 査読

Takahiro Chikamori, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

The 20th International Symposium on Wireless Personal Multimedia Communications (WPMC 2017) 229 - 233 2017年

Nonlinear Precoding for XOR Phisical Layer Network Coding in Bidirectional MIMO Relay Systems 査読

田野哲

IEICE Transaction on Communications 100-B ( 3 ) 440 - 448 2017年

Simplified Maximum Likelihood Detection with Unitary Precoding for XOR Physical Layer Network Coding 査読

田野哲

IEICE Transaction on Communications 100-B ( 1 ) 167 - 176 2017年

An iterative noise cancelling receiver with soft-output LR-aided detection for collaborative reception. 査読

Satoshi Denno, Yuta Kawaguchi, Hidekazu Murata, Daisuke Umehara

The 19th International Symposium on Wireless Personal Multimedia Communications (WPMC 2016) 37 - 41 2016年

Success prioritized distributed coordination function 査読

Daisuke Umehara, Hidekazu Murata, Satoshi Denno

IEICE COMMUNICATIONS EXPRESS 5 ( 9 ) 303 - 308 2016年

担当区分：最終著者記述言語：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 letter, we present a random access protocol with success priority, success prioritized distributed coordination function (SP-DCF), based on IEEE 802.11 DCF. Success stations (STAs) are prioritized contentionlessly to transmit the next data frame in the transmit queue in a random manner. We develop a performance analysis model of SP- DCF which enables us to estimate a variety of performance indexes such as the throughput or the frame discard rate (FDR) in a high accuracy for saturated wireless networks. The numerical analysis and simulation results show that the proposed SP-DCF achieves higher throughput and lower FDR as compared with the conventional DCF especially for heavily-congested wireless networks.

DOI： 10.1587/comex.2016XBL0083

5. 仮想伝搬路を適用した過負荷MIMO伝送技術

田野哲

映像情報メディア学会誌 70 ( 1 ) 23 - 27 2016年

センサネットワーク用適応送信型センサ協調ビーム形成法査読

藤田将大, 別府多久哉, 冨里繁, 田野哲, 秦正治

電子情報通信学会論文誌 B J98-B ( 10 ) 1146 - 1154 2015年10月

Physical layer network coding using THP for Bi-directional MIMO relay systems

Lengchi Cao, Satoshi Denno

2015 IEEE Wireless Communications and Networking Conference, WCNC 2015 1482 - 1487 2015年6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：Institute of Electrical and Electronics Engineers Inc.

Bi-directional relaying has been demonstrated to raise transmission throughput intensively as large as twice in throughput by applying physical layer network coding (PNC) when a pair of terminals exchange information via relay. With the aim to enhance the performance of relay system based on decode-and-amplify (DF) strategy, we propose a PNC scheme using Tomlinson-Harashima precoding (THP). Assuming the same broadcast scheme, our proposed scheme shows better performance than conventional linear precoding scheme. To reduce the transmission power without increasing bit error rate (BER), we further introduce a power controlling (PC) structure. It is proved that the transmission power and BER can both be reduced with the power controlling method.

DOI： 10.1109/WCNC.2015.7127687

An Iterative MIMO Receiver Employing Virtual Channels with a Turbo Decoder for OFDM Wireless Systems. 査読

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

IEICE Trans. Commun. 98-B ( 5 ) 878 - 889 2015年

Performance evaluation of device discovery in bluetooth LE with probabilistic model checking. 査読

Yusuke Matsuo, Daisuke Umehara, Hidekazu Murata, Satoshi Denno

IEICE 10th Asia-Pacific Symposium on Information and Telecommunication Technologies (APSITT) 1 - 3 2015年

An overloaded MIMO receiver with extended rotation matrices for virtual channels. 査読

Satoshi Denno, Akihiro Kitamoto

The Asia Pacific Conference on Communications, APCC'15 52 - 56 2015年

Transmission characteristics of OFDM packets in 5 GHz band using USRP. 査読

Satoshi Nakao, Daisuke Umehara, Hidekazu Murata, Satoshi Denno

10th Asia-Pacific Symposium on Information and Telecommunication Technologies(APSITT) 1 - 3 2015年

IEEE 802.11 DCF with Successful Transmission Priority 査読

Daisuke Umehara, Hidekazu Murata, Satoshi Denno

2015 9TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS) 2015年

担当区分：最終著者記述言語：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 distributed coordination function with successful transmission priority (DCF-STP) based on IEEE 802.11 DCF. DCF-STP will enhance the throughput and reduce the frame discard rate (FDR) in wireless networks because the wireless station (WS) just after the successful transmission has an opportunity to transmit the next frame without contention. We also develop a performance analytical model which enables to estimate the throughput, FDR, and the average number of frame retransmissions with high accuracy for saturated wireless networks. The simulation results show the validity of the developed performance analytical model of DCF-STP and the characteristics in the coexistence of the conventional DCF and the proposed DCF-STP.

Difference Analysis in IEEE 802.11 DCF 査読

Daisuke Umehara, Hidekazu Murata, Satoshi Denno

2015 10th Asia-Pacific Symposium on Information and Telecommunication Technologies (APSITT) 2015年

担当区分：最終著者記述言語：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, a simple and accurate estimation on performance of the original IEEE 802.11 distributed coordination function (DCF) is presented. The performances obtained from the Bianchi's analytical model of the IEEE 802.11 DCF are compensated by means of (1) the number of consecutive successful transmissions and (2) the deferred slot time. The compensated performances including throughput, packet loss rate, and the average number of transmissions approximate to the simulation results with a high degree of accuracy under a number of conditions even when the minimum contention window is small. The analytical and simulation results show us the possibility of performance improvement by the sender priority.

Transmit beamforming with DOA estimation in fast fading channels with AOA spread 査読

Satoshi Denno, Shigeru Tomisato, Masaharu Hata, Tatsuo Furuno, Yasuhiro Oda

2014 International Symposium on Antennas and Propagation Conference Proceedings 2014年12月

Iterative SVD-based frequency offset estimation with decorrelation for wireless sensor networks 査読

Satoshi Denno, Masataka Hasebe, Shigeru Tomisato, Masaharu Hata

2014 International Symposium on Wireless Personal Multimedia Communications (WPMC) 2014年9月

A non-linear distortion noise power control method for multi-band OFDM transmission 査読

Shohei Masaki, Shigeru Tomisato, Satoshi Denno, Masaharu Hata, Tatsuo Furuno, and Yasuhiro Oda

Proc. of the 17th International Symposium on Wireless Personal Multimedia Communications, WPMC 2014 748 - 753 2014年

A Virtual Channel Detector for Iterative Receiver in Overloaded MIMO OFDM Systems 査読

Satoshi Denno, Akihito Taya, Masahiro Morikura

2014 8TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS) 2014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

Iterative MIMO receivers with virtual channel are known to outperform linear detectors in overloaded multiple-input multiple-output systems with orthogonal-frequency division multiplex (MIMO-OFDM). This paper proposes a novel virtual channel detector that enables iterative MIMO receivers to achieve superior performance to the conventional receivers. Moreover, this paper proposes a novel signal estimation technique named as "extended maximum a posteriori probability (MAP) estimation" to select more reliable virtual channel. The proposed technique estimates the virtual channel with not only the a priori information on the virtual channels but also that on the real signals. The performance of the proposed detector with the extended MAP estimation is verified in a 6 x 2 MIMO OFDM system where the Turbo code is applied. The receiver with the proposed detector achieves much better performance than the conventional receivers. Actually, the proposed detector enables the MIMO receiver to achieve a gain of 3.0 dB at the BER of 10(-5), compared with conventional receivers with virtual channels, e.g., the soft input soft output (SISO) MAP detector with the same Turbo decoder. It is confirmed that the proposed receiver has by about one-fifth less complexity than the receiver with the SISO MAP MIMO detector.

DOI： 10.1109/ICSPCS.2014.7021069

Complexity Reduced Lattice-Reduction-Aided MIMO Receiver with Virtual Channel Detection 査読

Shogo Yoshikawa, Satoshi Denno, Masahiro Morikura

IEICE TRANSACTIONS ON COMMUNICATIONS E96B ( 1 ) 263 - 270 2013年1月

担当区分：責任著者記述言語：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

This paper proposes a lattice-reduction-aided MIMO-OFDM receiver with virtual channels; the receiver enables an increase in the downlink transmission speed for a user where the number of transmit antennas is considerably higher than that of the receive antennas. However, the receiver has a higher computational complexity than conventional lattice-reduction-aided MIMO receivers. Accordingly, we also propose novel techniques to reduce the computational complexity for the lattice-reduction-aided MIMO receivers with virtual channels. The proposed MIMO receiver achieves superior performance in 10 x 2 MIMO-OFDM systems. Furthermore, the proposed techniques are shown to reduce the computational complexity to approximately 40% of the original configuration in the 10 x 2 MIMO-OFDM systems.

DOI： 10.1587/transcom.E96.B.263

Software Radio-Based Distributed Multi-User MIMO Testbed: Towards Green Wireless Communications 査読

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

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES E96A ( 1 ) 247 - 254 2013年1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

The present paper introduces a prototype design and experimental results for a multi-user MIMO linear precoding system. A base station and two mobile stations are implemented by taking full advantage of the software-defined radio. The base station consists of general purpose signal analyzers and signal generators controlled by a personal computer. Universal software radio peripherals are used as mobile stations. Linear spatial precoding and a simple two-way channel estimation technique are adopted in this experimental system. In-lab and field transmission experiments are carried out, and the bit error rate performance is evaluated. The impact of the channel estimation error under average channel gain discrepancy between two mobile stations is analyzed through computer simulations. Channel estimation error is shown to have a greater influence on the mobile station with the greater average channel gain.

DOI： 10.1587/transfun.E96.A.247

Frequency Domain Imbalance Estimation in Heterodyne Multimode/Band Receivers with Baseband Automatic Gain Control 査読

Satoshi Denno, Ke Liu, Tatsuo Furuno, Masahiro Morikura

IEICE TRANSACTIONS ON COMMUNICATIONS E96B ( 1 ) 271 - 280 2013年1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

This paper proposes a novel scheme called as "frequency domain imbalance estimation" that estimates the imbalance of the Hilbert transformer in heterodyne multimode/band receivers with baseband automatic gain control (AGC). The proposed scheme uses correlation matrices in the frequency domain. This enables the receivers to keep high transmission performance in spite of the imbalance of the analog Hilbert transformer, by offsetting the imbalance. Moreover, the baseband AGC relaxes the requirement of the baseband AID converter. The performance of imbalance estimation and imbalance cancellation is verified by computer simulation. As a result, it is shown that the proposed scheme not only estimates the imbalance of Hilbert transformer with extremely high precision, but also cancels the image-band interference such that it achieves the theoretical performance.

DOI： 10.1587/transcom.E96.B.271

Iterative frequency offset estimation based on singular value decomposition

Masataka Hasebe, Satoshi Denno, Shigeru Tomisato, Masaharu Hata

Proc. of 2013 International Symposium on Intelligent Signal Processing and Communication Systems, ISPACS 2013 125 - 130 2013年

Indoor Experiment of Multi-User MIMO User Selection Algorithm Based on Chordal Distance 査読

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

2013 IEEE GLOBAL COMMUNICATIONS CONFERENCE (GLOBECOM) 3959 - 3964 2013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

A transmission experiment of a multi-user MIMO system with user selection and linear spatial precoding is conducted and the results are reported. As a low-complexity user selection algorithm, the chordal distance-based user selection (CDUS) algorithm is employed. The testbed used in the experiment is implemented by taking full advantage of the software-defined radio. An amplify-and-forward-based simple channel estimation method is adopted. As a result of the experiment in a conference room, the CDUS algorithm improved both the power efficiency and the interference suppression accuracy compared to the round-robin user selection.

DOI： 10.1109/GLOCOM.2013.6831692

A reduced-complexity heterodyne multiband MIMO receiver with estimation of analog devices imperfection in a baseband feedback loop 査読

Tomoya Ohta, Satoshi Denno, Masahiro Morikura

IEICE Transactions on Communications E96-B ( 6 ) 1540 - 1550 2013年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Institute of Electronics, Information and Communication, Engineers, IEICE

This paper proposes a reduced-complexity multiband multiple-input multiple-output (MIMO) receiver that can be used in cognitive radios. The proposed receiver uses heterodyne reception implemented with a wide-passband band-pass filter in the radio frequency (RF) stage. When an RF Hilbert transformer is utilized in the receiver, image-band interference occurs because of the transformer's imperfections. Thus, the imperfection of the Hilbert transformer is corrected in the intermediate frequency (IF) stage to reduce the hardware complexity. First, the proposed receiver estimates the channel impulse response in the presence of the strong image-band interference signals. Next, the coefficients are calculated for the correction of the imperfection at the IF stage, and are fed back to the IF stage through a feedback loop. However, the imperfection caused by the digital-to-analog (D/A) converter and the baseband amplifier in the feedback loop corrupts the coefficients on the way back to the IF stage. Therefore, the proposed receiver corrects the imperfection of the analog devices in the feedback loop. The performance of the proposed receiver is verified by using computer simulations. The proposed receiver can maintain its performance even in the presence of strong image-band interference signals and imperfection of the analog devices in the feedback loop. In addition, this paper also reveals the condition for rapid convergence. Copyright © 2013 The Institute of Electronics.

DOI： 10.1587/transcom.E96.B.1540

A low complexity heterodyne multiband MIMO receiver with baseband automatic gain control 査読

Tomoya Ohta, Satoshi Denno, Masahiro Morikura

IEICE Transactions on Communications E96-B ( 12 ) 3124 - 3134 2013年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Institute of Electronics, Information and Communication, Engineers, IEICE

This paper proposes a novel heterodyne multiband multiple-input multiple-output (MIMO) receiver with baseband automatic gain control (AGC) for cognitive radios. The proposed receiver uses heterodyne reception implemented with a wide-passband band-pass filter in the radio frequency (RF) stage to be able to receive signals in arbitrary frequency bands. Even when an RF Hilbert transformer is utilized in the receiver, image-band interference occurs due to the imperfection of the Hilbert transformer. In the receiver, analog baseband AGC is introduced to prevent the baseband signals exceeding the voltage reference of analogto- digital converters (ADCs). This paper proposes a novel technique to estimate the imperfection of the Hilbert transformer in the heterodyne multiband MIMO receiver with baseband AGC. The proposed technique estimates not only the imperfection of the Hilbert transformer but also the AGC gain ratio, and analog devices imperfection in the feedback loop, which enables to offset the imperfection of the Hilbert transformer. The performance of the proposed receiver is verified by using computer simulations. As a result, the required resolution of the ADC is 9 bits in the proposed receiver. Moreover, the proposed receiver has less computational complexity than that with the baseband interference cancellation unless a frequency band is changed every 9 packets or less. Copyright © 2013 The Institute of Electronics, Information and Communication Engineers.

DOI： 10.1587/transcom.E96.B.3124

A Convolutional Coded XOR Physical Layer Network Coding with Unitary Precoding in Wireless Bidirectional Relay Networks 査読

Satoshi Denno, Daisuke Umehara

2013 7TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS) 2013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

Physical layer network coding is able to improve frequency utilization efficiency in bi-directional wireless communications via a relay. This paper proposes a novel error correction scheme for physical layer XOR network coding. The proposed scheme not only improves transmission performance but also to reduce complexity at the relay. The proposed scheme applies a unitary precoding to offset phase rotation in the channel by exploiting the reciprocity between channels in the uplink and the downlink in systems with time division duplex (TDD). Moreover, a novel complexity reduced maximum likelihood detection technique is applied in the proposed scheme. It is evaluated by computer simulation that the proposed scheme attains a gain of 8dB at BER=10(-5) compared with AF network coding in a system with the use of OFDM.

Experimental Comparison of Linear Prediction Schemes for Multi-User MIMO Systems 査読

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

2013 11TH INTERNATIONAL SYMPOSIUM ON MODELING & OPTIMIZATION IN MOBILE, AD HOC & WIRELESS NETWORKS (WIOPT) 95 - 100 2013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 a multi-user multiple-input multiple-output (MU-MIMO) system, zero-forcing precoding can completely eliminates inter-user interference when the perfect channel state information is available at the base station. However, in time-varying channels, the transmission performance of MU-MIMO systems is severely degraded due to inter-user interference. In this paper, channel prediction is employed for channel tracking, and in-lab experiments are carried out to confirm its performance. The bit error rate (BER) performance is measured and compared with the computer simulation results. Both in-lab experiments and the computer simulations show that channel prediction improves the BER performance.

Complexity Reduced Lattice-Reduction-Aided MIMO Receiver with Virtual Channel Detection 査読

田野哲

IEICE Transaction on Communications E96-B 247 - 254 2012年12月

A Virtual Layered Successive Detector with Adaptive Transmit Signal Phase Rotation for QAM 査読

DENNO Satoshi, IMAMURA Jun, MORIKURA Masahiro

IEICE transactions on communications 95 ( 10 ) 3232 - 3241 2012年10月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：The Institute of Electronics, Information and Communication Engineers

This paper proposes a virtual layered successive detector with adaptive transmit signal phase rotation for quadrature amplitude modulation (QAM) that enables high speed communication even in downlinks of wireless communication systems. It is shown that the detection performance is degraded when the eigenvalue of a virtual channel becomes close to the power of the additive white Gaussian noise (AWGN). Therefore, adaptive transmit signal phase rotation is introduced for the detector to improve the transmission performance. For the transmit phase rotation, three techniques to search the rotation angles are proposed, which can reduce the feedback information from the receiver to the transmitter. Among the three proposed techniques, the technique called "iterative variable step step search" is shown to achieve the best performance. Actually, it is confirmed by computer simulation that the variable step search makes the detector attain about 17dB of a gain at the bit error rate (BER) of 10^-5 in 4×2 multiple-input-multiple-output (MIMO) systems.

DOI： 10.1587/transcom.E95.B.3232

A Least Bit Error Rate Adaptive Array for MultiLevel Modulations 査読

DENNO Satoshi, UMEHARA Daisuke, MORIKURA Masahiro

IEICE transactions on communications 95 ( 1 ) 69 - 76 2012年1月

This paper proposes an adaptive algorithm for adaptive arrays that minimizes the bit error rate (BER) of the array output signals in radio communication systems with the use of multilevel modulation signals. In particular, amplitude phase shift keying (APSK) is used as one type of multilevel modulations in this paper. Simultaneous non-linear equations that are satisfied by the optimum weight vector of the proposed algorithm are derived and used for theoretical analyze of the performance of the adaptive array based on the proposed algorithm. As a result of the theoretical analysis, it can be shown that the proposed adaptive array improves the carrier to interference ratio of the array output signal without taking advantage of the nulls. Furthermore, it is confirmed that the result of the theoretical analysis agrees with that of computer simulation. When the number of the received antenna is less than that of the received signals, the adaptive array based on the proposed algorithm is verified to achieve much better performance then that based on the least mean square (LMS) algorithm.

DOI： 10.1587/transcom.E95.B.69

A Virtual Successive Detection for Cooperative MU-MIMO Systems with Reduced CSI 査読

田野哲

Proceedings of the IEEE 75th Vehicular Technology Conference 1 1 - 5 2012年

Field Experiments of Linearly Precoded Multi-User MIMO System at 5 GHz Band 査読

Masato Taniguchi, 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, implementation of a multi-user MIMO experimental system is presented. Linear spatial precoding and a simple two-way channel estimation technique are adopted in the experimental system. In-lab and field transmission experiments are carried out and the performance is evaluated. The impact of channel estimation error under average channel gain discrepancy between two mobile stations is analyzed by means of computer simulation. It is shown that channel estimation error has a greater influence on the mobile station with greater average channel gain.

Partitioned Vector Quantization for MU-MIMO Downlink Broadcasting 査読

Mirza Golam Kibria, 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

A practical and efficient vector quantization called partitioned vector quantization (P-VQ) based non-linear precoder for MIMO downlink broadcasting channels has been analyzed in this paper. P-VQ has been found to be an efficient way of reducing the memory requirements and search complexity in conventional VQ systems, especially for large MIMO. Simulation results reveal that P-VQ technique can enhance the overall quantization performance in terms of achieved capacity, bit error rate (BER) at a cost of reasonable additional complexity under certain feedback budgets. Tomlinson-Harashima precoding (THP), a power and complexity efficient precoding technique along with data dependent vector perturbation (VP) has been employed to meet the power constraint requirements of our system. Least-square (LS) channel estimation is performed at the user terminals to acquire their channel state information (CSI).

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.

Coded Packet Immediate Access for Contention-Based Wireless Relay Networks 査読

Daisuke Umehara, Satoshi Denno, Masahiro Morikura, Takatoshi Sugiyama

2010 4TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS) 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 proposes a medium access control (MAC) protocol with network coding on relay nodes for contention-based multihop wireless relay networks. The proposed protocol is called coded packet priority access (CPPA) protocol in which coded packets have higher transmission opportunity than non-coded native packets at relay nodes. In this paper, the performance of coded packet immediate access (CPIA) protocols, which are a subclass of CPPA protocols, is evaluated for single-relay bidirectional symmetric traffic and upper and lower bounds of analytical throughput are derived for any given node traffic. It is shown that the lower bound approximates to the throughput obtained from computer simulations with high accuracy. The conventional slotted ALOHA protocol with network coding (SALOHA/NC) is required to adapt the transmission probability of relay node to a rational function of node traffic so as to maximize the throughput whereas the CPIA protocol achieves the maximal throughput only if the relay node transmits no native packets. Furthermore it is clarified that the CPIA protocol is superior to the S-ALOHA/NC protocol in delay for given retransmission probabilities of user nodes.

Achievable Region in Slotted ALOHA Throughput for One-Relay Two-Hop Wireless Network Coding 査読

Daisuke Umehara, Satoshi Denno, Masahiro Morikura, Takatoshi Sugiyama

AD HOC NETWORKS 28 376 - + 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：SPRINGER-VERLAG BERLIN

This paper presents achievable regions in slotted ALOHA throughput both without and with network coding for one-relay two-hop wireless networks between two end node groups. In this paper, there are no restrictions on the total traffic and the number of end nodes per group. It follows that the relay node will be generally involved with asymmetric bidirectional traffic. This paper derives closed-form expressions of the throughput and packet delay per group both without and with network coding from a theoretical perspective regardless of whether the buffer on the relay node is saturated or not. Furthermore, we show that the maximum throughput per group with network coding can be achieved at the boundary of the relay buffer saturation and unsaturation which is expressed as the solution of a polynomial equation in two group node traffics. As a result, we clarify the enhancement of the achievable region in slotted ALOHA throughput by applying network coding.

An Iterative Parallel OFDM Demodulation for Fast Time-Varying Fading Channels 査読

田野哲

Proceedings of 4th international conference on signal processing and communication systems 1 2010年

Throughput analysis of two-hop wireless CSMA network coding 査読

Daisuke Umehara, Satoshi Denno, Masahiro Morikura, Takatoshi Sugiyama

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）

DOI： 10.1109/ICC.2010.5502114

Iterative Decoding on Soft Information for Virtual Layered Space-Frequency Receivers 査読

Jun Imamura, Satoshi Denno, Daisuke Umehara, Masahiro Morikura

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

In this paper, we propose an iteration scheme for the virtual layered space frequency communication architecture. The architecture enables the decoding of the transmitted orthogonal frequency division multiplexing (OFDM)-QPSK signals even if the number of spatial multiplexed layers is twice that of receiving antennas over multipath fading channels. In the proposed iteration scheme, the MAP decoder and detector exchange soft information on the virtual channel. Using the soft informations, the architecture achieves much higher performance with lower computational complexity compared to maximum likelihood detection (MLD) even when the punctured code is used. Consequently, a gain of 4.5 dB can be achieved at a BER of 10-3 compared to that achieved with the MLD in the 4 x 2 MIMO-OFDM system when the rate 3/4 punctured code is used. The performance of the proposed architecture is verified by carrying out computer simulations.

MIMO空間多重伝送における仮想伝搬路判定を適用した逐次復号法

丸山浩史, 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 92 ( 10 ) 1677 - 1686 2009年10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

MIMO空間多重伝送を用いた無線通信の復号方法の一つに,逐次復号法がある.逐次復号法を利用する場合,送信アンテナ数は受信アンテナ数の同等以下である必要がある.この条件が空間多重伝送の伝送容量を制限していた.本論文では,この条件を緩和し伝送容量を拡大できる新しい直列型逐次復号器の構成を提案する.提案する直列型逐次復号器では,"仮想伝搬路"という概念を導入することで,仮想的に受信アンテナ数を2倍たする.これにより,送信アンテナ数が受信アンテナ数よりも多い場合にも復号を可能にする.このことを計算機シミュレーションにより確認する.

Blind Image-Band Interference Canceller Based on CM (Constant Modulus) Criteria for Multimode Receivers

DENNO Satoshi, FURUNO Tatsuo, MORIKURA Masahiro

IEICE transactions on communications 92 ( 9 ) 2903 - 2914 2009年9月

This paper proposes a blind image-band interference canceller that enables heterodyne receivers with only a single receiver chain to demodulate signals in any frequency band. In this paper, such a receiver is called "multimode/multiband heterodyne receiver." If multimode/multiband receivers are desired to receive signals with carrier frequency ranging from several MHz to GHz, then, such receivers are not allowed to have a narrow band RF-BPF (Radio Frequency Band Pass Filter) at the RF front end. However, although heterodyne receivers have been applied to wireless systems due to their high performance, it is known that without an RF-BPF heterodyne receivers suffer from severe image-band interference. Therefore, a blind image-band interference canceller is proposed in this paper to mitigate the image-band interference. Moreover, a novel algorithm based on the CM (Constant Modulus) criterion is proposed to carry out the cancellation. Performance of the blind image-band interference canceller is theoretically analyzed and the performance of the proposed canceller is verified by computer simulation. As a result, it is shown that the blind image-band interference canceller achieves superior performance even in the presence of strong image-band interference, for example, CIR=-40dB. In summary, the proposed canceller makes it possible for the receiver with the single receiver chain to achieve multimode/multiband communications with high quality.

DOI： 10.1587/transcom.E92.B.2903

高速フェージング伝送路のための並列FFT等化

橋本幸一郎, 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 92 ( 7 ) 1174 - 1184 2009年7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

FFT等化は簡易なハードウェア構成で優れたマルチパスフェージング耐性を有するが,高速フェージング環境下では等化器出力にひずみが発生し,著しく伝送特性が劣化する.本論文では,この特性劣化を抑圧する並列FFT等化器を提案する.並列FFT等化器では,異なる時刻におけるチャネルインパルス応答を用いて並列にFFT等化を行い,その出力を合成する.更に,フェージングひずみによる特性劣化を抑圧するため,ひずみ補償法も並列化し各等化器に備える.加えて,高速に変動する伝送路を高精度に推定するため,等化復号後の信号を利用した繰返し伝送路推定を適用する.提案する等化器の伝送特性を計算機シミュレーションにより評価し,従来のFFT等化器に比べ大幅に誤り率が改善できることを示す.

Wireless Network Coding in Slotted ALOHA with Two-Hop Unbalanced Traffic 査読

Daisuke Umehara, Tomoya Hirano, Satoshi Denno, Masahiro Morikura, Takatoshi Sugiyama

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 27 ( 5 ) 647 - 661 2009年6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：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

This paper deals with two representative unbalanced traffic cases for two-hop wireless relay access systems employing network coding and a slotted ALOHA protocol. Network coding is a recent and highly regarded technology for capacity enhancement with multiple unicast and multisource multicast networks. We have analyzed the performance of network coding on a two-hop wireless relay access system employing the slotted ALOHA under a balanced bidirectional traffic. The relay nodes will generally undergo this unbalanced multidirectional traffic but the impact of this unbalanced traffic on network coding has not been analyzed. This paper provides closed-form expressions for the throughput and packet delay for two-hop unbalanced bidirectional traffic cases both with and without network coding even if the buffers on nodes are unsaturated. The analytical results are mainly derived by solving queueing systems for the buffer behavior at the relay node. The results show that the transmission probability of the relay node is a design parameter that is crucial to maximizing the achievable throughput of wireless network coding in slotted ALOHA on two-hop unbalanced traffic cases. Furthermore, we show that the throughput is enhanced even if the traffic at the relay node is unbalanced.

DOI： 10.1109/JSAC.2009.090607

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

Jun Imamura, Satoshi Denno, Daisuke Umehara, Masahiro Morikura

GLOBECOM 2009 - 2009 IEEE GLOBAL TELECOMMUNICATIONS CONFERENCE, VOLS 1-8 6339 - 6344 2009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 study, we develop a virtual layered space-frequency communication architecture. This architecture enables the decoding of transmitted OFDM (Orthogonal Frequency Division Multiplexing)-QPSK signals even if the number of antennas at the transmitter is twice the number of antennas at the receiver over multipath fading channels. Furthermore, we propose two detection schemes called "hard replica" and "soft replica." In addition, in order to improve the performance of this architecture, we propose an iteration in which the receiver decodes the detected signals; through such iterations, this architecture can obtain path diversity and achieve high performance. When the transmitter has four antennas and receiver has two antennas, the proposed architecture achieves HER of 8 x 10(-4) using the soft replica at E-b/N-0 = 15 dB. Furthermore, by performing more iterations, it provides additional gains of 3 dB. The performance of the proposed architecture is verified using computer simulations.

Influences of periodically switching channels synchronized with power frequency on PLC equipment 査読

Daisuke Umehara, Taro Hayasaki, Satoshi Denno, Morikura Masahiro

Journal of Communications 4 ( 2 ) 108 - 118 2009年

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

The regulation on power line communication (PLC) has been eased in Japan, and the frequency band between 2 and 30 MHz can be used for in-home PLC. Several different types of commercial PLC equipment are available in the market. Almost all of them include PLC adapters that interconvert Ethernet signals and power line signals. An in-home network can easily be constructed by using these PLC adapters because there are many power outlets in every room. However, there are various factors that tend to destabilize the communication among PLC adapters. These factors involve time-varying channel response and noise characteristics, which are both synchronized with the power frequency. In particular, it has been observed that the noise in a power line varies more significantly than the channel response. Therefore, many PLC adapters contain certain features to mitigate the time-varying noise in a power line. We show a number of examples of more significant variations in the channel response synchronized with the power frequency due to the switching regulators used. This paper deals with such a time-varying channel response synchronized with the power frequency. We show that the performance of the PLC adapters suffers due the time-varying channel response and analyze its influences on the PLC adapters. © 2009 Academy Publisher.

DOI： 10.4304/jcm.4.2.108-118

A Simulator of Periodically Switching Channels for Power Line Communications 査読

Taro Hayasaki, Daisuke Umehara, Satoshi Denno, Masahiro Morikura

ACCESS NETS 6 162 - 175 2009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：SPRINGER-VERLAG BERLIN

An indoor power line is one of the most attractive media for in-home networks. However, there are many technical problems for achieving in-home power line communication (PLC) with high rate and high reliability. One of such problem is the degradation in the performance of the in-home PLC caused by periodically time-varying channel responses, particularly when connecting the switching power supply equipment. We present a measurement method for power line channel responses and reveal the switching of the channel responses synchronized with power-frequency voltage when connecting switching power supply equipment in sending or receiving outlets. In this paper, we term them periodically switching channel responses. The performance of PLC adapters is seriously affected by the periodically switching channel responses. Therefore, we provide a modeling of the periodically switching channel responses by using finite impulse response (FIR) filters with a shared channel memory and construct a simulator for in-home power line channels including the periodically switching channel responses in order to evaluate the various communication systems through the power line. We present the validity of the proposed simulator through the performance evaluation of OFDM/64QAM over periodically switching channels with additive white Gaussian noise. Furthermore, we evaluate the influence of the periodically switching channel responses on the communication quality of a time-invariant modulation scheme by using the proposed simulator.

A Virtual Layered Space Time Receiver with Maximum Likelihood Channel Detection

DENNO S.

Proc. IEEE VTC' 09 Spring, Barcelona, April 2009年

Throughput Analysis of Wireless Relay Slotted ALOHA Systems with Network Coding 査読

Daisuke Umehara, Tomoya Hirano, Satoshi Denno, Masahiro Morikura

GLOBECOM 2008 - 2008 IEEE GLOBAL TELECOMMUNICATIONS CONFERENCE 2008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

This paper deals with a simple but essential two-hop wireless relay network employing network coding and a slotted ALOHA protocol. Network coding is a recent and highly regarded technology for capacity enhancement on multiple unicast and multisource multicast networks. However, the performance of network coding on wireless relay networks employing random access protocols has not been analyzed. This paper provides closed-form expressions for the throughput and delay on two-hop wireless relay networks both with and without network coding from a theoretical perspective of the slotted ALOHA protocol. The analytical results are derived by solving queueing systems for the buffer activity at the relay node. The results show that the transmission probability of the relay node is a design parameter that is crucial to maximizing the achievable throughput of slotted ALOHA with network coding on a twohop wireless relay network. Furthermore, this paper clarifies that the throughput is enhanced by controlling the transmission probability of the relay node such that it has considerable opportunity for network coding.

DOI： 10.1109/GLOCOM.2008.ECP.953

ヘテロダインマルチモード受信における決定論的補償行列推定

林大祐, 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 91 ( 11 ) 1440 - 1449 2008年11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

マルチモードバンド受信を単一のRF回路により実現するために,ヘテロダイン受信機においてRFフィルタを取り除き,RF帯にアナログヒルベルト変換器を用いる構成が知られている.ところが,マルチモードバンド受信が扱う広範囲な周波数帯においてアナログヒルべルト変換器の特性を理想的に保つことは困難であり,その結果,イメージ干渉が発生し,伝送特性が劣化する問題があった.本論文ではヒルべルト変換器の不完全性をブラインド処理により高速に推定する決定論的手法を提案する.そして,提案手法がOFDMやCDMA方式において,10サンプル程度で所望の推定精度を達成することを示す.また,提案手法に基づく干渉抑圧法が強力なイメージ干渉下でも,所望信号を必要とせずとも高速にイメージ干渉を抑圧できることを示す.

デュアル周波数変換型ヘテロダインマルチモード・マルチバンド受信機

林大祐, 古野辰男, 田野哲

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 91 ( 5 ) 566 - 574 2008年5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

ヘテロダイン受信機では,マルチモード化するためにRFフィルタを除去すると,イメージ干渉が発生し,伝送特性を劣化させる.そのため,従来この干渉を適応的に抑圧する技術が提案されている.ただし従来技術では,収束に時間がかかるという問題があった.そこで,本論文では,所望信号とイメージ信号の両方をベースバンド帯に変換し,その後にMMSE規範に基づいて重み付け加算することで,イメージ干渉を除去する方式を提案する.計算機シミュレーションにより,提案手法が高速な収束特性と優れた耐干渉性能を有することを示す.

The influence of time-varying channels synchronized with commercial power supply on PLC equipments 査読

Daisuke Umehara, Taro Hayasaki, Satoshi Denno, Masahiro Morikura

IEEE ISPLC: 2008 IEEE INTERNATIONAL SYMPOSIUM ON POWER LINE COMMUNICATIONS AND ITS APPLICATIONS 30 - 35 2008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

The regulation on power line communication (PLC) has been eased in Japan and the frequency band between 2 and 30 MHz can be exploited for in-home PLC. Several commercial PLC equipments are available in the market. Almost all PLC equipments take on a form of PLC adapters interconverting Ethernet signals and power line signals. We can construct in-home network by these PLC adapters easily because there are many power outlets in every room. However there are various factors destabilizing the communication among PLC adapters. These factors involve time-varying channel response and noise characteristics which are synchronized with commercial power supply. In particular, it has been seen that the noise on power line has significant variations rather than the channel response. Therefore, many PLC adapters are taking some measures to mitigate the time-varying noise on power line. On the other hand, we show a number of examples of more significant variations of the channel response synchronized with power supply due to some kinds of switching regulators. In this paper, we deal with such the time-varying channel response synchronized with commercial power supply. We show that the PLC adapters suffer from the time-varying channel response and analyze its influence on the PLC adapters.

An Initial Acquisition Method for Channel Synchronization on In-home Power Line Communications 査読

Keita Watanabe, Daisuke Umehara, Satoshi Denno, Masahiro Morikura

ISPLC: 2009 IEEE INTERNATIONAL SYMPOSIUM ON POWER LINE COMMUNICATIONS AND ITS APPLICATIONS 137 - 142 2008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 an initial acuisition method for channel synchronization on in-home broadband power line communication (PLC). It has been considered that the time fluctuation in the transfer function has been smaller than that in the noise on the in-home broadband PLC. However, we have observed that the extensively and rapidly time fluctuation across the whole frequency band appears in the in-home PLC at the half of power cycle intervals while connecting some switching power supply devices. Such largely and quickly, time fluctuation makes the extensive degradation in performance of in-home PLC devices. Therefore, we should estimate the timing of time fluctuation and synchronize the in-home PLC systems with the estimated time fluctuation. We evaluate the performance of the proposed initial acquisition method under impulsive noise environments and investigate its feasibility for the real in-home PLC.

Power Saving Effect of Sensor Collaborative Beam Forming for Wireless Ubiquitous Network Systems

Sousuke Tokunaga, Yoshihisa Kawakami, Kenichi Hashimoto,*Shigeru Tomisato, Satoshi Denno, and Masaharu Hata

Proc. CD of the 14th Asia-Pacific Conference on Communications (APCC2008) 301 - + 2008年

A Bit-Loaded OFDMA for In-home Power Line Communications 査読

Taro Hayasaki, Daisuke Umehara, Satoshi Denno, Masahiro Morikura

ISPLC: 2009 IEEE INTERNATIONAL SYMPOSIUM ON POWER LINE COMMUNICATIONS AND ITS APPLICATIONS 171 - 176 2008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

The in-home broadband power line communication (PLC) is drawing attention to us lately. The broadband PLC has regulation issues for the coexistence with shortwave wireless systems. Therefore, orthogonal frequency division multiplexing (OFDM) is adopted for the broadband PLC. On the other hand the power line channels suffer from frequency selective fading. It is effective to load appropriate bits on each subcarrier in the OFDM for PLC. In this paper, we propose a bit loading algorithm that maximizes the bit rate by optimizing not only the bit quantity on each subcarrier but also the whole code rate of the forward error correction (FEC) code subject to constraints on the total bit error rate (BER) and power on each subcarrier. Furthermore, we investigate orthogonal frequency division multiple access (OFDMA) as a multiple access scheme on the in-home power line networks. We show that the proposed OFDMA scheme is superior to a time division multiple access (TDMA) scheme from the viewpoint of throughput by computer simulations.

A fast bit loading algorithm synchronized with commercial power supply for in-home PLC systems 査読

Shinya Honda, Daisuke Umehara, Taro Hayasaki, Satoshi Denno, Masahiro Morikura

IEEE ISPLC: 2008 IEEE INTERNATIONAL SYMPOSIUM ON POWER LINE COMMUNICATIONS AND ITS APPLICATIONS 336 - 341 2008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-home PLC (Power Line Communication) is one of the most attractive in-home networkings. However, there are a lot of technical issues for the realization of PLC with high rate and high reliability. These issues include the influence of frequency selective and linear periodically time-variant (LPTV) channel synchronized with commercial power supply. In particular, we show that some kind of switching power devices impact deep and deterministic time selectivity for power line channels. The combination of OFDM (Orthogonal Frequency Division Multiplexing) and bit loading algorithm is a powerful tool to increase the bit rate or reliability for quasi-static frequency selective channels including power line channels. However, a quick response will be required for the execution of bit loading algorithm since power line channels are synchronized with commercial power supply. In this paper, we propose a fast bit loading algorithm based on the fractional knapsack algorithm to enhance the bit rate under the condition that the transmitted power is constant. Furthermore, we evaluate the achievable bit rate of the proposed algorithm for the SNR over a power line channel and compare it with the achievable bit rate based on water filling theory.

Performance evaluation of CSK/PAM system using optimized real-valued sequence 査読

Daisuke Ueyama, Daisuke Umehara, Satoshi Denno

2007 IEEE INTERNATIONAL SYMPOSIUM ON POWER LINE COMMUNICATIONS AND ITS APPLICATIONS 28 - + 2007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

We propose applying pulse amplitude modulated code shift keying (CSK/PAM) to indoor power line communication (PLC) for the high-speed data transmission at the low electromagnetic wave leakage. However, CSK/PAM system using conventional binary sequence, for example Gold sequence and M sequence, has error floor for real power line channels even with rake receiver because of the poor properties of odd auto and cross-correlation. Therefore, we propose extending binary sequence to real-valued sequence and we optimize performance in real-valued sequence by minimizing the even and odd, autoand cross-correlation values. We show that the CSK/PAM system using the optimized real-valued sequence can achieve better BER (Bit Error Rate) performance as compared with that using Gold sequence by computer simulation.

Performance evaluation of wavelet OFDM using ASCET 査読

Keita Izumi, Daisuke Umehara, Satoshi Denno

2007 IEEE INTERNATIONAL SYMPOSIUM ON POWER LINE COMMUNICATIONS AND ITS APPLICATIONS 245 - + 2007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

Power line communication (PLC) is one of the most attractive communication methods for in-home networks. However, the emissions of unwanted electric waves from PLC system cause harmful interference to other radio communication systems with the same frequency band. Wavelet OFDM (Orthogonal Frequency Division Multiplexing) is expected to be an efficient modulation for PLC because it can make steep and deep notch for any frequency band in the transmit signal power spectrum. However, wavelet OFDM cannot implement the equalization by guard interval (GI) like OFDM and causes performance degradation in multipath channels including power line channels. In this paper, we apply ASCET (Adaptive Sine modulated / Cosine modulated filter bank Equalizer for Transmultiplexers) to wavelet OFDM and evaluate its performance over a multipath power line channel. In particular, we propose an estimation scheme of equalizer coefficients for ASCET that the required preamble becomes short. We compare the performance of OFDM with GI to that of wavelet OFDM with ASCET over the multipath power line channel by computer simulations. As a result, we show that the proposed scheme can achieve the approximately equivalent performance of OFDM with GI by using the shorter preamble as compared to the original scheme.

A new decoding of tornado-like codes over packet loss and error channels

D. Umehara, S. Denno

25th AIAA International Communications Satellite Systems Conference 2007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：American Institute of Aeronautics and Astronautics Inc.

The satellite communication is suitable for the multicast communication because it can broadcast multiple receiving stations over a wide area. The FEC (forward error correction) like tornado-like codes is effective for balk data transmission in the satellite multicast because the packet retransmission is inefficient. The tornado-like codes are exploited for the packet losses by the buffer overflow or congestion control. Yamato et al. proposed an effective decoding against bit errors remained in the packets for tornado-like codes by exploiting a bit-by-bit majority decision. We call this decoding Yamato decoding. In this paper, we propose a new decoding whose performance is improved for that of Yamato decoding. We show the performance of the proposed decoding by computer simulations and is superior to that of Yamato decoding. © 2007 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

DOI： 10.2514/6.2007-3267

A decoding for low density parity check codes over impulsive noise channels 査読

H Nakagawa, D Umehara, S Denno, Y Morihiro

2005 International Symposium on Power Line Communications and Its Applications 85 - 89 2005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

Power line channel often suffers from impulsive interference generated by electrical appliances. Therefore, power line communication makes degradation due to such impulsive interference. We introduce Middleton's Class A noise model into a statistical model of impulsive noise environment.
In this paper, we apply LDPC (Low Density Parity Check) codes and sum-product decoding to additive white Class A noise (AWAN) channels. We propose a sum-product decoding which is suitable for AWAN channels. In addition, we show the BER (Bit Error Rate) performance of the proposed sum-product decoding in Class A noise environment by computer simulation.

<大学の研究・動向> 衛星通信アクセス系における大容量データ伝送実験

森広芳照, 田野哲, 梅原大祐

Cue : 京都大学電気関係教室技術情報誌 14 2 - 6 2004年12月

Adaptive image-band interference canceller based on CM (constant modulus) criteria for multimode receivers

DENNO S.

IEEE VTC'04-Spring 2004年

Recursive vector Viterbi algorithm for multibeam interference cancellers

DENNO S.

Proc. IEEE VTC, 2003 3 1890 - 1894 2003年

Development of an adaptive array based on subband signal processing 査読

Y Kamiya, S Denno, Y Mizuguchi, M Katayama, A Ogawa, Y Karasawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART III-FUNDAMENTAL ELECTRONIC SCIENCE 85 ( 10 ) 19 - 30 2002年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SCRIPTA TECHNICA-JOHN WILEY & SONS

Adaptive arrays for spatiotemporal signal processing are expected to be effective multipath measures in future high-speed mobile communications systems. However, a problem is the tremendous computational load in a hardware implementation because the number of weights that are adaptively controlled becomes extremely large. There fore, the key to its practical use is to reduce the computational load. In this paper, an adaptive array for processing subband signals that can substantially reduce the computational load was implemented in hardware by using a commercially available digital signal processor (DSP). First, we illustrated the scale of the hardware by the number of DSPs needed in each unit that performed the required signal processing. Next, we built a simple multipath environment of two waves in an anechoic chamber and performed experiments to demonstrate the basic performance and veri fled that performance nearly equal to the theoretical values was obtained. (C) 2002 Wiley Periodicals, Inc.

DOI： 10.1002/ecjc.1122

Performance and configuration of M-CMA (modified constant modulus algorithm) adaptive array using polyphase filters 査読

Satoshi Denno, Takashi Ohira

Electronics and Communications in Japan, Part I: Communications (English translation of Denshi Tsushin Gakkai Ronbunshi) 85 ( 12 ) 53 - 64 2002年

掲載種別：研究論文（学術雑誌）

As a way to realize an adaptive array of small size, low cost, and low power consumption, there exists a configuration method combining analog signal processing and digital signal processing. M-CMA has been proposed as a control algorithm for such an approach. However, when this approach is applied to an actual communication system, there arises the problem that the narrow-band filter in the receiver prevents M-CMA from converging to the desired solution. In this paper, in order to effectively operate an M-CMA adaptive array in the presence of a narrow-band filter, a configuration is proposed in which polyphase filters are used as narrow-band filters. Its superior interference suppression capability is confirmed by a theoretical analysis and computer simulation.

DOI： 10.1002/ecja.10021

ポリフェーズフィルタを適用した M-CMA アダプティブアレーの構成と特性

田野哲, 大平孝

電子情報通信学会論文誌. B, 通信 84 ( 10 ) 1796 - 1806 2001年10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

アダプティブアレーを小型・低価格, 低消費電力で実現する方法として, アナログ信号処理とディジタル信号処理を融合した構成法があり, その制御アルゴリズムとしてM-CMAが提案されている.ところが, 実際に通信システムに適用する場合には, 受信機に備えられる狭帯域フィルタが, M-CMAを希望解に収束させないという問題を起こす.そこで本論文では, M-CMAアダプティブアレーを狭帯域フィルタの存在下でも効果的に動作させるため, 狭帯域フィルタにポリフェーズフィルタを応用する構成を提案している.そして, その優れた干渉抑圧特性を理論解析及び計算機シミュレーションにより確認している.

100-Mbit/s single-chip Q-VLMS MLSE equalizer LSI for TDMA mobile radio communications

Yushi Shirato, Kiyoshi Kobayashi, Satoshi Denno

IEEE Journal of Solid-State Circuits 36 ( 8 ) 1178 - 1185 2001年8月

記述言語：英語掲載種別：研究論文（学術雑誌）

A single-chip 100-Mbit/s burst-operation two-tap maximum likelihood sequence estimation (MLSE) equalizer LSI for QPSK signals is introduced. It also supports two-branch diversity combining. Three new techniques are used to realize this fast equalizer LSI: the quantized variable-gain least mean squares (VLMS) algorithm, which has small processing delay with fast convergence characteristics
a simple complex-valued multiplication scheme based on inverting the sign and switching the in-phase and quadrature-phase components
and a parallel structure to minimize the processing delay of path memory. The chip, containing 75 kgates, is manufactured using the 0.45-μm-CMOS gate array process. The supply voltage is 3.3 V. This LSI offers higher processing speed than any other conventional equalizer chip for mobile radio communications.

DOI： 10.1109/4.938368

Algorithm Diversity in a Software Antenna

KARASAWA Yoshio, KAMIYA Yukihiro, INOUE Takashi, DENNO Satoshi

IEICE transactions on communications 83 ( 6 ) 1229 - 1236 2000年6月

記述言語：英語出版者・発行元：一般社団法人電子情報通信学会

Asoftware antenna, which will be a key device realizing flexible and highly reliable wireless communications systems, is inherently matched with software defined radios(SDR).In this paper, first, key technologies on the software antenna are introduced. The technologies contain i)how to recognize the radio environment, ii)how to determine the optimum adaptive signal processing algorithm, and iii)how to reconfigure the digital beamforming circuit. Then, an image of a software antenna with reconfigurable eigenvector-beamspace configuration is presented. Finally, by assuming various propagation conditions, performance of the software antenna in terms of algorithm diversity is demonstrated.

Modified constant modulus algorithm for digital signal processing adaptive antennas with microwave analog beamforming

DENNO S.

IEEE Aerospace Conference. Big Sky 2000年

M-CMA for digital signal processing adaptive antennas with microwave beamforming

DENNO S.

2000 IEEE Aerospace Conf., Big Sky, Montana, Mar. 5 179 - 187 2000年

A Software Antenna: Reconfigurable Adaptive Arrays Based on Eigenvalue Decomposition

KAMIYA Yukihiro, KARASAWA Yoshio, DENNO Satoshi, MIZUGUCHI Yoshihiko

IEICE transactions on communications 82 ( 12 ) 2012 - 2020 1999年12月

記述言語：英語出版者・発行元：一般社団法人電子情報通信学会

Multimedia mobile communication systems are expected to be realized in the near future. In such systems, multipath fading can cause severe degradations of the quality of the communications due to its wide bandwidth, especially in urban areas. Adaptive array antennas can be attractive solution for overcoming the multipath fading. Suppression can be achieved with the adaptive array by cophasing and combining multipath signals in the space and time domain. On the other hand, the concept of software antenna has been proposed. The software antenna recognizes radiowave environments and appropriately reconfigures itself for the signal processing required by the recognized environment. Efficient implementations can be expected if these functions are realized by the software. In this paper, we propose two types of the adaptive array systems which is reconfigurable depending on the radiowave environment as a realization of the concept of the software antenna. They recognize the environment by using the eigenvalue decomposition of space domain correlation matrices and reconfigure their structures of the signal processing. The principle and performance are examined by theoretical means and through computer simulations.

Orthogonal-transformed variable-gain least mean squares (OVLMS) algorithm for fractional tap-spaced adaptive MLSE equalizers 査読

S. Denno, Y. Saito

IEEE Transactions on Communications 47 ( 8 ) 1151 - 1160 1999年

40 Mbit/s adaptive MLSE equalizer LSI and its performance in 5 GHz-Band transmission system

Yushi Shirato, Kiyoshi Kobayashi, Satoshi Denno

IEEE VTS 50th Vehicular Technology Conference, VTC 1999-Fall 1 305 - 308 1999年

掲載種別：研究論文（学術雑誌）

The authors have developed a single chip, 40 Mbit/s operation, 3-tap MLSE equalizer LSI. The LSI supports burst operation and is available for both QPSK and π/4-QPSK modulated signals. This paper shows the performance of a 5 GHz-Band 40 Mbit/s experimental system using this equalizer LSI. The main results are as follows; 1) The implicit diversity gain offered by the equalizer is 12 dB at the BER of 10-3. 2) The gain obtained in 2-branch diversity reception is 6 dB at the BER of 10-3. 3) In single branch operation, no error floor is observed when the BER is higher than 10-4. Furthermore, 2-branch diversity reception limits the irreducible bit errors to one tenth that of single branch reception. 4) The DC offset compensator effectively minimizes the degradation introduced by the DC offset caused by the imperfection of the demodulator. 5) The same performance is observed for both modulation schemes. The LSI can be used in wide band wireless applications like indoor wireless LAN systems and wide area wireless local loop systems.