An Improved Variable Step-Size Dual-Mode Blind Equalization Algorithm for QAM Signals

An Improved variable step-size dual-mode blind equalization algorithm for QAM signals is proposed in this paper. The algorithm which is combining the decision feedback equalizer (DFE) structure uses a variable step-size in its start-up mode to speed up its convergence rate, and then switches to the directed decision (DD) as the tracking mode to reduce the residual error after convergence. Simulation results show that the proposed algorithm has a faster convergence rate and lower residual error, and can compensate the phase rotation automatically.