The fusion blind equalization algorithm based on constant modulus algorithm and decision direction with parallel filter

To solve the problem of switching time of dual-mode blind equalization algorithm for CMA (Constant Modulus Algorithm) and DD (Decision Direction), a dual-mode blind equalization algorithm with parallel filter is proposed. The weights of subfilters update with CMA and DD algorithm respectively, the weighting factor is adjusted according to normalized mean square error with the iterative times that controls the dual-mode algorithm adaptive switch, which implement the fusion process. To prevent the channel sudden interference, Information entropy increment of normalized mean square error is defined as criterion for resetting of the weighting factor and the weights of filter, thus can ensure the stability of the algorithm under the channel sudden interference. Simulation analysis and the pool experiments show that the proposed algorithm can make full use of the advantages of the two algorithms and has better performance.