大气湍流对激光通信系统的影响

从分析激光在大气湍流场中的传输方程出发,忽略系统中的其它噪声,仅考虑由大气喘流引起的系统误码率,讨论了激光信号在传输过程中的振幅起伏以及强度起伏;推导出由大气湍流引起的光强起伏和系统误码率的关系,结果表明:在弱起伏条件下,对于系统误码率为10－9以下的要求,光强起伏应小于0.67;随着湍流强度C2n的增大,误码率增加很快;采用长波长的激光进行传输可以有效地降低系统误码率.

Effect of the atmospheric turbulence on laser communication system

First,transmission equation of the laser transmitting through atmospheric turbulence channel was analyzed,ignoring other noises in the system,atmosphere turbulence was the only cause for Bit Error Rate(BER).Then,the amplitude variance and intensity variance of the laser signal were discussed,and the relationship betwwen BER and the laser communication system was deduced.The result indicated that in the weak variance condition intensity variance should be below 0.67 for communication system with BER below 10 -9;with turbulence intensity C2_n increasing,BER increased rapidly;adopting laser with longest wave to communicate can decrease BER effecively.