研究者詳細 - 山里　敬也

論文 - 山里　敬也

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An initial code acquisition scheme for indoor packet DS/SS systems with macro/micro antenna diversity 査読有り

Y Ikai, M Katayama, T Yamazato, A Ogawa

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES E83A 巻 ( 11 ) 頁： 2070 - 2077 2000年11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, we study macro/micro diversity techniques for code acquisition of a direct-sequence spread-spectrum signal in an indoor packet communication system. In the system discussed, the base station has several radio ports each with a cluster of antennas, and the terminal also has multiple antennas. The performance in the uplink of this system is analyzed under Lognormal shadowing and flat Rayleigh fading. The numerical results show great performance improvements by proposed diversity techniques. In addition, it is clarified that the mean acquisition time, which is often used as the measure of performance, is not suitable for packet radio systems as it underestimates the necessary preamble length for initial code acquisition.

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An initial code acquisition scheme for indoor packet DS/SS systems with macro/micro antenna diversity 査読有り

Ikai Y, Katayama M, Yamazato T, Ogawa A

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES E83A 巻 ( 11 ) 頁： 2070 - 2077 2000年11月

An access control protocol for a heterogeneous traffic with a multi-code CDMA scheme 査読有り

A Sandouk, T Yamazato, M Katayama, A Ogawa

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES E83A 巻 ( 11 ) 頁： 2085 - 2092 2000年11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, we discuss the access control in multimedia CDMA ALOHA protocol. We introduce a new algorithm for the access control based on Modified Channel Load Sensing Protocol (MCLSP) in an integrated Voice and two different classes of data users, high bit rate and low bit rate, exist in a multi-code CDMA Slotted ALOHA system. With our new algorithm, we show that the throughput of high bit rate data users, as well as, the total throughput of the data medium can be optimized and take a maximum value even at high values of offered loads. We also investigate the performance when voice activity detection (VAD) is considered in voice transmission.

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A Study on Reducing tne Nonlinear Distortion in Multicarrier Systems 査読有り

HARADA Masaaki, YAMAZATO Takaya, KATAYAMA Masaaki, OGAWA Akira

IEICE Trans. Fundamentals, A 83 巻 ( 10 ) 頁： 1992 - 1995 2000年10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：The Institute of Electronics, Information and Communication Engineers

In this paper, we discuss on the realization of reduced peak power transmission for the multicarrier systems. Since the signals have large amplitude fluctuations in conventional multicarrier systems, signals amplified by a nonlinear amplifier are greatly distorted, resulting in severe performance degradation. In order to avoid this large amplitude fluctuation, we propose a scheme for reducing the nonlinear distortion by using the set of the signal point series which show low peak to mean envelope power ratio(PMEPR)value. In this system, one symbol is transmitted with multicarriers and the received signal is detected with maximum likelihood sequence detection.

CiNii Research

An Study on Reducing the Nonlinear Distortion on Multicarrier Systems 査読有り

M. Harada, T. Yamazato, M. Katayama, A. Ogawa

電子情報通信学会論文誌 E83-A 巻 ( 10 ) 頁： 1992-1995 2000年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

In this paper, we discuss on the realization of reduced peak power transmission for the multicarrier systems. Since the signals have large amplitude fluctuations in conventional multicarrier systems, signals amplified by a nonlinear amplifier are greatly distorted, resulting in severe performance degradation. In order to avoid this large amplitude fluctuation, we propose a scheme for reducing the nonlinear distortion by using the set of the signal point series which show low peak to mean envelope power ratio (PMEPR) value. In this system, one symbol is transmitted with multicarriers and the received signal is detected with maximum likelihood sequence detection.

A study on reducing the nonlinear distortion in multicarrier systems 査読有り

Harada M, Yamazato T, Katayama M, Ogawa A

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES E83A 巻 ( 10 ) 頁： 1992 - 1995 2000年10月

A-5-9 逐次型干渉除去を用いたCDMA Unslotted ALOHA方式における2種類のパケット存在検出誤りの影響査読有り

田所幸浩, 岡田啓, 齋藤将人, 山里敬也, 片山正昭, 小川明

電子情報通信学会ソサイエティ大会講演論文集 2000 巻頁： 145 2000年9月

Joint optimization of transmitter/receiver with multiple transmit/receive antennas in band-limited channels 査読有り

Ban K, Katayama M, Yamazato T, Ogawa A

IEICE TRANSACTIONS ON COMMUNICATIONS E83B 巻 ( 8 ) 頁： 1697 - 1704 2000年8月

Joint optimization of transmitter/receiver with multiple transmit/receive antennas in band-limited channels 査読有り

K Ban, M Katayama, T Yamazato, A Ogawa

IEICE TRANSACTIONS ON COMMUNICATIONS E83B 巻 ( 8 ) 頁： 1697 - 1704 2000年8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

We study the joint optimization problem of a transmitter with multiple transmit antennas and a receiver with multiple receive antennas in a narrow-band communication system. We discuss the problem of designing a pre-filter at the transmitter, a post-filter at the receiver, and a bit allocation pattern to multiple symbols in the sense of minimizing the average bit error rate. With the optimized filters and the bit allocation, we could realize high efficiency and high data rate in band-limited channels.

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Adaptive Transmit Permission Probability Control in CDMA Cellular Packet Communications with Site Diversity 査読有り

MORI Kazuo, KOBAYASHI Takehiko, YAMAZATO Takaya, OGAWA Akira

IEICE transactions on communications 83 巻 ( 7 ) 頁： 1445 - 1453 2000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：The Institute of Electronics, Information and Communication Engineers

Site diversity causes unfairness in packet reception that depends on the location of the mobile stations in the uplink of CDMA cellular packet communication systems.This paper proposes an adaptive transmit permission probability control scheme that reduces this unfairness in CDMA cellular slotted-ALOHA systems with site diversity.The proposed scheme adaptively controls the transmit permission probability according to the offered load and the location of the mobile stations.Successful packet reception rate, fairness coefficient and throughput performance are evaluated in fading environments with imperfect power control.Computer simulation shows that adaptive transmit permission probability control improves fairness of service for all mobile stations and throughput performance across all channel loads compared with the conventional scheme.

CiNii Research

Adaptive transmit permission probability control in CDMA cellular packet communications with site diversity 査読有り

Mori K, Kobayashi T, Yamazato T, Ogawa A

IEICE TRANSACTIONS ON COMMUNICATIONS E83B 巻 ( 7 ) 頁： 1445 - 1453 2000年7月

Adaptive transmit permission probability control in CDMA cellular packet communications with site diversity 査読有り

K Mori, T Kobayashi, T Yamazato, A Ogawa

IEICE TRANSACTIONS ON COMMUNICATIONS E83B 巻 ( 7 ) 頁： 1445 - 1453 2000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

Site diversity causes unfairness in packet reception that depends on the location of the mobile stations in the uplink of CDMA cellular packet communication systems. This paper proposes an adaptive transmit permission probability control scheme that reduces this unfairness in CDMA cellular slotted-ALOHA systems with site diversity. The proposed scheme adaptively controls the transmit permission probability according to the offered load and the location of the mobile stations. Successful packet reception rate, fairness coefficient and throughput performance are evaluated in fading environments with imperfect power control. Computer simulation shows that adaptive transmit permission probability control improves fairness of service for all mobile stations and throughput performance across all channel loads compared with the conventional scheme.

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階層チャネル割当て方式を用いた低軌道衛星通信システムのハンドオーバ特性

原司, 片山正昭, 岡田啓, 山里敬也, 小川明

電子情報通信学会技術研究報告 SAT 巻頁： - 2000年6月

マルチビーム低軌道衛星通信システムにおける多元接続方式の性能比較

市川直樹, 片山正昭, 岡田啓, 山里敬也, 小川明

電子情報通信学会技術研究報告 SAT2000 巻頁： - 2000年6月

Effects of cell structure on quality of service of LEOS communication systems 査読有り

Ono K, Katayama M, Yamazato T, Ogawa A

IEICE TRANSACTIONS ON COMMUNICATIONS E83B 巻 ( 4 ) 頁： 782 - 790 2000年4月

Effects of cell structure on quality of service of LEOS communication systems 査読有り

K Ono, M Katayama, T Yamazato, A Ogawa

IEICE TRANSACTIONS ON COMMUNICATIONS E83B 巻 ( 4 ) 頁： 782 - 790 2000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

In this paper, we analytically study the effects of overlap and overlay structure on the quality of service (QoS) of Low Earth-Orbital Satellite (LEOS) communication systems. We consider two-layered overlay of cells and intentional overlap of neighboring small cells. In order to measure the QoS, the probabilities of rejection of a newly arrived call (blocking) and Forced termination due to failure of a handover (call dropping) are derived. In addition to these measures, the largest traffic intensity which guarantees the required blocking and dropping probabilities is also used.

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パケット検出誤りを考慮した逐次型干渉除去を適用したCDMA Unslotted ALOHA方式の特性評価

田所幸浩, 岡田啓, 齋藤将人, 山里敬也, 片山正昭, 小川明

2000年電子情報通信学会総合大会頁： - 2000年3月

無線環境下におけるTCPの解析モデルに関する一検討

内藤克浩, 岡田啓, 齋藤将人, 山里敬也, 片山正昭, 小川明

2000年電子情報通信学会総合大会 B-5-185 巻頁： 570 2000年3月

無線環境下におけるTCPのスループット解析に関する一検討

内藤克浩, 岡田啓, 斎藤将人, 山里敬也, 片山正昭, 小川明

電子情報通信学会無線通信システム研究会 99 巻 ( 638 ) 頁： 107 - 113 2000年2月

Modeling of Cyclostationary and Frequency Dependent Power-Line Channels for Communications 査読有り

M. Katayama, S. Itou, T.Yamazato, A. Ogawa

The 4th International Symposium on Power-Line Communications and its Applications ISPC 巻頁： - 2000年

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