分散協力無線ネットワークの伝送技術

摘要

In this paper, transmission techniques in distributed cooperative communication are introduced. Multi--hop relaying can extend communication range using limited transmit power, and improve the area spectral efficiency. However, it brings considerable degradation of end-to-end error rate performance due to error propagation along the hops. Cooperative relaying, in which multiple stations relay the received signal using transmit diversity techniques, can recover the errors unless all the relay stations do not receive the signal correctly, and improve the end-to-end transmission performance. In this paper, the FER performance of multi-hop cooperative networks is analyzed by using state transition. Theoretical analysis reveals that the FER performance can be kept almost constant, or even improved with increasing the number of the hops. And also, radio equipments for field trials are briefly explained together with some technical key points. Finally, the SINR performance of the multi-user spatial precoding scheme with a two-way channel estimation technique is revealed.%複数の無線局が協力して伝送を行う分散協力無線ネットワークにおける伝送技術を紹介している．送信ダイバーシチ中継を行うマルチホップ協力無線通信システムでは，各無線リンクの通信距離短縮による空間的周波数利用効率の改善効果と総送信電力の削減効果に加えて，協力中継によるEnd-to-End 誤り率特性の改善効果が得られる．条件によってはホップ数とともに誤り率特性が改善する現象が生じるが．この理論的裏付けを紹介している．次に，マルチホップ協力伝送のフィールド実験装置の概略を示している．最後に，分散した多数の送受信点を用いるマルチユーザ空間プリコーディングシステムについても取り上げ，チャネル推定を行った場合のSINR 特性を明らかにしている．