基于DSP算法的光相干检测通信MSK信号研究

Research on Optical Coherent Detection Communication MSK Signal Based on DSP Algorithm

为了解决光相干检测通信MSK信号出现的相位偏移和信号幅度失真问题,结合MSK信号的连续相位调制特点,对常数模均衡算法进行了改进,提出了改进后的CMA算法,并利用其来消除MSK信号的残余误差。结果表明,在没有加入相位噪声的情况下,该算法能够对MSK的全部噪声进行消除,在加入相位噪声后,与传统的CMA算法相比,该算法得到的误码率最小为10^(-5),且能消除所有残余误差,具有更好的效果,说明该算法能够完整有效地恢复出光相干通信系统的MSK信号,具有一定的参考价值。

In order to solve the phase shift and signal amplitude distortion of MSK signal in optical coherent detection communication,the constant modulus equalization algorithm is improved based on the continuous phase modulation characteristics of MSK signal.An improved CMA algorithm is proposed and used to eliminate the residual error of MSK signal.The results show that the algorithm can eliminate all the MSK noise without adding phase noise.After adding phase noise,compared with the traditional CMA algorithm,the minimum bit error rate of the algorithm is 10^(-5),and all residual errors can be eliminated.The algorithm has better effect.It shows that the algorithm can recover the MSK signal of the optical coherent communication system completely and effectively,and has certain practical value.