Research of Blind Equalization Technology of Coherent Optical Communication Based on Decidion Optimization

In order to improve the equalization performance of the coherent optical communication system. Improve the problems of Godard blind equalization algorithm under non-cooperative communication such as large steady-state error and weak convergence. A decision optimized blind equalization method based on modified constant modulus algorithm (MCMA) and variable step size direct decision least mean square (VSSDDLMS) algorithm is proposed. Use different functional modules to implement the MCMA and VSSDDLMS algorithms. The new algorithm combines the characteristics of MCMA algorithm stability and DDLMS algorithm with small steady-state errors, and introduces the autocorrelation estimation of the error function to control the step size update. Experimental results show that the constellation diagram of the new algorithm converges tightly and the steady-state error is small, the bit error rata is low. The algorithm effectively improves the anti-jamming capability of the communication system, and can be applied to the fields of optical communication, satellite communication, radar and other fields.