长波红外无线激光通信脉冲宽度调制实验研究

为实现长波红外无线激光通信,建立了基于脉宽调制的长波红外无线激光通信系统模型,对系统性能进行了分析,给出了系统误码率的计算公式.搭建了实验系统,对CO_2激光器的平均输出光功率随占空比的变化情况进行了分析,对不同占空比条件下接收端对应的激光平均脉冲宽度以及脉冲宽度受噪声影响的随机变化情况进行了分析,得到了激光输出平均光功率、平均脉冲宽度与占空比之间的关系,以及脉宽的分布规律,并将实验结果与理论分析结果进行了对比,在此基础上得到了脉宽最佳判决门限和系统各类工作参数同误码率之间的关系.结果表明,基于CO_2激光器的脉冲宽度调制能够实现长波红外无线激光通信.

Experimental Study of Pulse Width Modulation in Long-wave Infrared Wireless Optical Communication

In order to realize a Long-wave Infrared (LWIR) optical wireless communication,a long-wave infrared optical wireless communication system model based on pulse width modulation was estabished,the performance of this system was analyzed,and an expression of bit error rate was proposed.An experimental system was designed,the change of average output optical power of CO2 laser was analyzed,the average of received laser pulse width and random variation of pulse width affected by the noise under different duty ratios were analyzed.The relationship between the average of output optical power and pulse width with duty ratio was obtained,and the distribution law of pulse width was also obtained,and then the experimental results and theory analysis results were compared,based on this,the optimal judgment threshold of pulse width and the relationship between system working parameters with (Bit Error Rate)BER were obtained.It is proved that a long-wave infrared optical wireless communication can be achieved based on CO2 laser by the pulse width modulation.