A blind equalizer allowing soft transition between the constant modulus and the decision-directed algorithm for PSK modulated signals

An algorithm for the blind equalization of PSK modulated signals is proposed. This algorithm is inspired by both the constant modulus algorithm (CMA) and the decision directed (DD) algorithm, and it is shown that it keeps the desired properties of both (robustness far from the convergence position and precision near this position). Furthermore, it allows a phase correction of the output (which is not the case in the constant modulus algorithm) up to a fixed phase rectifiable by the code. A fast implementation, which allows a reduction of the arithmetic complexity, is provided. A comparison of the adaptive performances with the CMA and DD algorithm is provided in the radio-mobile context