空间光通信中分布式天线的信号检测研究

针对空间光通信中随机信道传播时延导致接收信号符号间干扰的特殊性使分布式发射天线多入多出(MIMO)信号的线性检测算法更加复杂这一问题,提出了一种基于Neyman-Pearson(NP)融合准则的分布式天线信号检测算法。仿真结果表明,当接收信号同步时,NP算法具有较好的健壮性,其性能优于等增益合并(EGC)算法,与最佳合并(OC)算法相当;当接收信号异步时,NP算法要明显优于EGC和OC算法,抑制接收符号间干扰,能体现出分布式天线系统的空间分集性能。

Signal detection algorithm in free-space optical communication systems with dis tributed transmit antennas

The distributed multiple-input multiple-output (MIMO) technique is one of the effective ways to mitigate the effect of atmospheric turbulence and reduce the packet error rate in free-space optical c ommunications.Because the time of laser propagation is different and random among atmospheric turbul ence links,signals arrive at the receiving antennas randomly and asynchronously,which causes the pr oblem of inter-symbol interference.But linear detection algorithms are more complicated to solve it f or the free-space optical (FSO) system with distributed transmit antennas.The valuable information obtaine d from signs of distributed receiving antennas depends on combining mode,and the performance of anti-interference is determined by the detection algorithm.Focusing on the problem above,this paper proposes the algorithm based on maximum likelihood detection and Neyman-Pearson (NP) fusion criterion for distributed receiving antennas system.Simulation results show that when receiv ing signal is synchronous, NP algorithm has better robustness,it is comparable to optimal com bining (OC) algorithm,and it is better than the equal gain combining (EGC) a lgorithm.When receiving signal is asynchronous, NP algorithm is better than EGC and OC algorithms,which improves spatial diversi ty performance in the distributed antennas system,suppressing inter-symbol interference.