研究者詳細 - 田野　哲

論文 - 田野　哲

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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.

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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.

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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.

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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

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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.

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<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

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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

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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.

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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

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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.

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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.

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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.

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6. 144Mbit/s Burst Modem with an Adaptive Equalizer for TDMA Mobile Radio Communications 査読

Satoshi DENNO, Yushi SHIRATO

IEICE Transaction on Communications E81-B ( 7 ) 1453 - 1461 1998年7月

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