分布式发射天线MIMO信号的最优线性检测

Optimal Linear Detection Algorithm of MIMO with Distributed Transmit Antennas

在分布式发射天线多输入多输出(MIMO)系统中,信道传播时延使各个发射天线的符号异步到达接收天线.接收信号符号间干扰的特殊性使分布式发射天线MIMO信号的线性检测算法更加复杂,最优线性检测算法也不能直接由最小均方误差(MMSE)准则得到.针对这一问题,提出了基于MMSE准则的分布式发射天线MIMO信号的最优线性检测算法:先最大比合并,再最小均方误差检测.并且,通过界定误码率上下限,得到其分集阶数.仿真结果验证了最优线性检测接收端信号处理方式的正确性.

For multiple-input multiple-output（MIMO）space-time coded architecture based on distributed antenna system（DAS）,signals from different transmit antennas arrive asynchronously to the receiving antennas due to the random channel propagation delays among different links.Consequently,linear detection algorithms may be more complicated because of the complexity of inter-symbol interference.Furthermore,the optimal linear detection algorithm would not be obtained directly by applying minimum mean square error（ MMSE） criterion. Focusing on the problem above, this paper supposes the optimal linear detection algorithm, named Joint-MMSE detection, in which maximum ratio combining（MRC） is implemented firstly, subsequently MMSE detection, and finally the diversity order by bounding bit error rate（BER）. According to the simulation results, MRC-MMSE is authentically the optimal linear detection algorithm of MIMO with distributed transmit antennas.