多输入多输出(MIMO)系统可以有效提高频谱效率和系统容量。基于MIMO系统重点研究了无线光通信垂直分层空时系统(v—BLAST)检测算法。首先分析了最大似然、线性迫零、最小均方误差以及排序千扰抵消等典型的传统检测算法,基于OOK调制和4PPM调制对采用不同检测算法的系统差错性能进行了仿真对比,最后对Turbo码与BLAST技术相结合构成的新系统采用了软输入软输出(siso)迭代检测译码方案。仿真结果表明,分层空时检测算法中性能最优的是ML,其次是SISO—MAP,ZF算法性能最差;Turbo.BLAST系统可以有效提高无线光通信系统的抗干扰性能。
Multi-Input Multi-Output (MIMO) system can greatly improve the spectrum efficiency and system capacity. Based on the analysis of MIMO system, a research on vertical stratification space-time system (V-BLAST) detection algorithm of wireless optical communication was made in depth. Firstly, several typical detection algorithms were studied as ML, ZF, MMSE and OSIC. Based on OOK and 4PPM modulation, the system BER performance using different detection algorithms was simulated. Then a new system combining Turbo and BLAST technique was put forward which used SISO iterative detection method. The simulation results show that among all layered space-time detection algorithms, the optical performance of ML is best, followed by SISO-MAP and ZF algorithrn, and Turbo-BLAST system could improve the anti-jamming performance of FSO.