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部分相干光在湍流大气中传输时,可以有效抑制湍流所引起的光强闪烁效应,从而改善通信链路性能。针对Gamma-Gamma大气湍流信道模型和部分相干光的光束特性,得到了采用OOK调制方式下部分相干光通信系统的平均误码率、中断概率和平均信道容量三个性能指标的解析表达式;在此基础上,分析了光束的空间相干长度和通信距离对通信链路的性能影响。计算结果表明,在相同的大气湍流条件和传输距离下,随着部分相干光的空间相干长度的减小,系统的误码率和中断概率逐步降低,在平均信噪比为30 dB时,系统的误码率可以达到10~(-5),中断概率低于10~(-6);另外,系统的平均信道容量会随着光束相干长度的减小而增加,在信噪比等于12 dB时,平均信道容量达到3.8 b/s·Hz~(-1)。分析结果为部分相干光在湍流大气中实现可靠通信提供了理论依据。
When partially coherent light is transmitted in a turbulent atmosphere, the effect of light intensity flicker caused by turbulence can be effectively suppressed, thereby improving the performance of the communication link. For Gamma-Gamma atmospheric turbulence channel model and partially coherent light beam characteristics, the analytical expressions of the average BER, the outage probability and the average channel capacity of the partially coherent optical communication system under OOK modulation are obtained. Based on this, the influence of beam coherence length and communication distance on the performance of communication link is analyzed. The results show that with the same atmospheric turbulence and transmission distance, as the spatial coherence length of partially coherent light decreases, the BER and the probability of outage decrease gradually. When the average SNR is 30 dB, the system The error rate can reach 10 -5 and the probability of outage is less than 10 -6. In addition, the average channel capacity of the system will increase with the decrease of the beam coherence length. When the SNR is equal to 12 dB , The average channel capacity reaches 3.8 b / s · Hz ~ (-1). The results provide a theoretical basis for the reliable communication of partially coherent light in turbulent atmosphere.