论文部分内容阅读
在自由空间光通信(FSO)中,多输入多输出(MIMO)可以大大提高频谱利用率。在对FSOMIMO进行分析研究的基础上,提出了垂直分层空时(V-BLAST)结构,建立了该结构的系统模型。分别取不同的MIMO组数,仿真比较了PPM和OOK两种调制方式的系统误码率。运用VHDL语言设计了垂直分层空时结构的编译码,并进行了硬件功能和时序仿真。研究结果表明:在信噪比一定的情况下,PPM调制方式下系统的误码率要低于OOK调制方式下系统的误码率;运用VHDL语言设计的V-BLAST编译码,从硬件功能和时序上验证了FSOMIMO系统的可行性。
In free-space optical communications (FSO), multiple-input multiple-output (MIMO) can greatly increase spectrum utilization. Based on the analysis of FSOMIMO, the vertical stratified space-time (V-BLAST) structure is proposed, and the system model of the structure is established. Taking different numbers of MIMO groups respectively, the system error rates of PPM and OOK are simulated. VHDL language was used to design a vertical layered space-time structure of the coding and decoding, and the hardware features and timing simulation. The results show that under the condition of certain signal-to-noise ratio, the bit error rate of the system under PPM modulation is lower than that of the system under OOK modulation. V-BLAST codec designed by VHDL language, Timing verify the feasibility of FSOMIMO system.