北京大学学报(自然科学版)

自适应CDMA匹配滤波接收机

蔡月民, 刘铁   

  1. 北京大学电子学系,北京,100871
  • 收稿日期:1997-05-19 出版日期:1998-09-20 发布日期:1998-09-20

Adaptive CDMA Matched-filtering Receiver

CAI Yuemin, LIU Tie   

  1. Department of Electronics, Peking University, Beijing, 100871
  • Received:1997-05-19 Online:1998-09-20 Published:1998-09-20

摘要: 研究了一种自适应DS-CDMA信号匹配滤波接收机。在这种接收机中,利用一个自适应匹配滤波器,根据最小均方误差准则,对接收匹配滤波器系数(参考向量)作自适应调整。在白噪声情况下,自适应接收机等效于传统匹配滤波器。当存在干扰和多径时,自适应接收机能够抑制干扰,合并多径,从而实现对发送信号的最佳检测。本文对多址干扰情况下接收机的性能进行了分析,并给出了仿真结果。结果表明,这种接收机的误码性能虽然随着用户数的增加恶化,但通过增加信噪比(Eb/N0),可以将误码降到任意低的水平。

关键词: 多址干扰, 自适应匹配滤波, 信号空间

Abstract: This paper presents an adaptive matched-filtering receiver for DS/CDMA signals. Under MMSE criterion, the adaptive receiver converges to a conventional single user matched filter for an AWGN channel. For interference and multipath channels, the adaptive receiver achieves optimal detection by interference suppression and multipath combination. This paper presents the analytical and simulation results of the receiver in synchronous and asynchronous multi-user channels. The results show that the adaptive matched-filtering receiver is near-far resistant. By only improving the SNR of expected user, the BER can be decreased to any expected level.

Key words: multiple access interference(MAI), adaptive matched filter, signal space

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