Multiple Access Methods for Low Earth-Orbital Satellite Communication Systems

近地轨道卫星通信系统的多址接入方法

• 批准号: 09650410
• 负责人: KATAYAMA Masaaki
• 金额: $ 2.18万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650410/
• 关键词: Low Earth-Orbital Satellite System; Multiple Access Methods; Satellite Communications; Handover; Channel Capacity; Cellular Radio; Overlay; Overlap; CDMA; チャンネル容量; 移動体通信; マルチメディア

In this research, multiple access methods for low earth-orbital satellite (LEOS) communication systems with multiple spot beams are investigated. In order to discuss the mitigation of handover failure and call blockings in TDMA systems, two-layered channel configuration is considered, where a part of satellite channels are reserved and assigned to the cells of fully loaded on demand assignment basis. Also, intentional overlap of adjacent cells are considered and found to have good handover performance. In addition to the discussion on TDMA, several features of CDMA scheme are studied. Since one of the most peculiar feature of LEOS systems is large Doppler shift in carrier frequency, PN code acquisition of a CDMA signal under Doppler shift is examined and the influence of the inter-satellite interference and the frequency offset is clarified. In CDMA systems, multiple access interference limits the maximum capacity of the systems. Thus interference cancellation techniques with a subtraction based nonlinear canceller and with a spatial cancellation by adaptive array antenna are also discussed. Though the discussion on the cancellation schemes are done for terrestrial systems, it is straight forward to apply them in LEOS systems.

本研究针对低轨卫星通信系统中多点波束的多址接入方式进行研究。为了讨论TDMA系统中切换失败和呼叫阻塞的缓解问题，考虑了两层信道配置，即保留一部分卫星信道，并按需分配给满载小区。此外，相邻小区的故意重叠被认为是具有良好的切换性能。除了对TDMA的讨论外，还研究了CDMA方案的几个特点。由于LEOS系统的最大特点之一是载波频率的大多普勒频移，研究了在多普勒频移下CDMA信号的PN码捕获，并阐明了星间干扰和频偏的影响。在CDMA系统中，多址干扰限制了系统的最大容量。因此，干扰消除技术与减法为基础的非线性抵消器和空间消除自适应阵列天线也进行了讨论。虽然对抵消方案的讨论是针对地面系统进行的，但将其应用于低地球轨道系统是直接的。

项目成果

N. Ichikawa, M. Katayama, T. Yamazato, A. Ogawa: "Influence of Beam Pattern on the Capacity of LEOS Communicaiton Systems"Proc. International Symposium on Communications. 1019-1027 (1999)

N. Ichikawa、M. Katayama、T. Yamazato、A. Okawa：“波束方向图对 LEOS 通信系统容量的影响”Proc。

K.Ono,M.Katayama,T.Yamazato,A.Ogawa: "Effects of Cell Structure on Quality of Service of LEOS (発行予定)"IEICE Trans.on Communications. Vol.E83-B,No.4未定. (2000)

K.Ono、M.Katayama、T.Yamazato、A.Okawa：“小区结构对 LEOS 服务质量的影响（待出版）” IEICE Trans.on Communications Vol.E83-B，No.4 待出版。确定（2000）。

A. Morimoto, M. Katayama, T. Yamazato, A. Ogawa: "Problems of Implementing Adaptive Array Antennas in CDMA Systems"PIMRC98. Vol.3. 1422-1426 (1998)

A. Morimoto、M. Katayama、T. Yamazato、A. Okawa：“在 CDMA 系统中实现自适应阵列天线的问题”PIMRC98。

K. Ono, M. Katayama, T. Yamazato, A. Ogawa: "Performance of a LEOS Communication System with Overlaid and Overlapped Cell Arrangement"Proc. of 3rd European Workshop on Mobile/Personal Satcoms. 131-145 (1998)

K. Ono、M. Katayama、T. Yamazato、A. Okawa：“具有重叠和重叠单元排列的 LEOS 通信系统的性能”Proc。

森本彰人,片山正昭 他: "CDMAシステムに適したアダプティブアレーアンテナの制御方式" 電子情報通信学会技研報告. CS 98-56. 7-14 (1998)

Akihito Morimoto、Masaaki Katayama 等人：“适用于 CDMA 系统的自适应阵列天线的控制方法”IEICE CS 98-56 (1998)。