A Variable Forgetting Factor RLS-CMA Algorithm Based on Decision Directed Scheme

In response to the severe distortion of the transmitted signal due to phase rotation after convergence of the RLS-CMA blind equalisation algorithm, a variable forgetting factor RLS-CMA algorithm based on decision-directed scheme is proposed in this paper. This new method adaptively adjusts the forgetting factor based on the mean square error and corrects the equalisation output using the DD algorithm to improve the channel tracking performance. The proposed method converges faster and reduces the steady-state residual error while compensating the phase distortion effectively. In addition, the steady state performance of the algorithm is verified by Taylor series expansion to ensure its accuracy.