孔径平均效应对采用相位补偿技术的空间相干光通信系统误码率的影响

基于大气湍流影响下的空间相干光通信系统模型和孔径平均效应的平面波模型,通过数值模拟研究了弱光强波动条件下孔径平均效应以及大气湍流内外尺度对相干光通信系统误码率和接收孔径直径最优值的影响。研究结果表明:孔径平均效应能够有效减小相干光通信系统的误码率,改善系统性能;原始信噪比越高,传输距离越短,波长越长,相位补偿模式的J值越大,接收孔径直径越接近最优值,孔径平均效应对误码率的改善效果越明显;孔径平均效应会影响接收孔径直径的最优值,相位补偿模式的J值越大,影响越明显;系统误码率和接收孔径直径最优值会随着大气湍流内尺度的增大而相应增大,随着大气湍流外尺度的减小而相应减小。研究结果将为空间相干光通信系统设计提供必要的理论依据。

Influence of Aperture Averaging on Bit-Error Rate of Spatial Coherent Optical Communication Systems Using Phase Compensation Technique

Based on the model of the spatial coherent optical communication system under the influence of the atmospheric turbulence and the plane-wave propagation model of aperture averaging, by using of numerical simulation, under the weak irradiance fluctuation condition the influence of aperture averaging including the atmospheric turbulence inner scale and outer scale is investigated on the bit-error rate and the optimum receiver aperture diameter of the coherent optical communication system. The results show that aperture averaging can decrease the bit-error rate effectively; the improved effect of aperture averaging on the bit-error rate is more obvious for the higher original SNR, the shorter transmission distance, the longer wavelength, the larger value of the phase compensation mode J and the receiver aperture diameter which is closer to the optimum value; aperture averaging affects the optimum value of the receiver aperture diameter, and if the value of the phase compensation mode J is larger, the influence is more obvious; the bit-error rate and the optimum receiver aperture diameter will increase with the increase of atmospheric turbulence inner scale and decrease with the decrease of atmospheric turbulence outer scale. This will provide the necessary theoretical basis for the design of a coherent optical communication system.