自由空间光通信(FSO)中的分层空时编码(LST),能极大地提高系统的传输速率,但误码率较大,严重影响光通信系统的可靠性。在分析了光强起伏的特性之后,建立了湍流信道中多输入多输出(MIMO)信道的模型;提出了采用串行干扰消除算法来完成FSO 中分层空时编码译码的方法,并和线性译码算法的性能进行了对比。最后,利用仿真实验进一步验证了该方法的可行性。结果表明:在FSO 中,采用串行干扰消除译码算法时的误码性能明显优于线性译码算法的误码性能。

Layered Space-time code (LST) in free space optical communication system can greatly improve system transmission speed rate, but the corresponding error rate of the method impacts the reliability of system badly. Firstly, based on the analysis of optical intensity fluctuation, a Multiple Input Multiple Output (MIMO) channel model is proposed. Secondly, the decoding of LST is completed by using Serial Interference Cancellation (SIC) in free space optical communication, and then its performance is compared with that of linear decode algorithm. At last, the feasibility of the technique is proved by simulation analysis, which shows that in free space optical communication system, the error-rate performance by using SIC algorithm in LST is better than that of linear decoding algorithm.