结合孔径平均技术, 研究了湍流和瞄准误差联合效应信道下圆偏振移位键 控 (CPOLSK) 调制的误码率和中断概率性能。基于 Meijer G 函数, 推导了 CPOLSK 调制误码率和中断概率的闭合表达式; 仿真研究了归一化波束宽度、归一化抖动标准差以及接收孔径对系统平均误码率、中断概率的影响, 进行了数值分析, 并与开关键控调制 (OOK) 的误码率进行了比较; 通过蒙特卡洛仿真, 对基于偏振调制的自由空间光 (FSO) 通信系统性能的数值分析结果进行了验证。结果表明: 同一条件下, CPOLSK 调制的误码率性能优于 OOK 调制; 归一化波束宽度对系统性能的影响是非线性的, 存在最优值; 随着归一化抖动标准差的增大, 系统的性能会下降; 增大接收孔径尺寸, 可以有效地提高系统的性能。研究结果对 FSO 通信系统的设计具有实际指导意义。

The average bit error rate (BER) and outage probability of circular polarization shift key (CPOLSK) modulation under the combined effect channel of atmospheric turbulence and pointing errors are investigated by using aperture averaging technique. The closed expressions of BER and outage probability are derived by using Meijer G function. The influences of normalized beamwidth, normalized jitter and receiver aperture size on the average BER and outageprobability are simulated, and numerical analysis is also carried out. And then the BER performance of CPOLSK modulation is compared with that of on-off keying (OOK) modulation. All numerical simulation results are verified by Monte-Carlo simulation. Results show that the BER performance of CPOLSK modulation is better than OOK modulation under the same conditon, and the influence of normalized beam width on system performance is nonlinear and there is an optimal value. It is also shown that with the increase of the normalized jitter standard deviation, the performance of the system will decrease, while increasing the receiving aperture size can effectively improve the performance of the system. The results are of practical significance for the design of FSO communication system.