Adaptive equalization of CPM signals transmitted over fast Rayleigh flat-fading channels

A new algorithm for adapting the coefficients of an equalizer for continuous phase modulated data signals in a flat-fading environment is presented. The cost function to optimize is based on the maximum likelihood sequence estimation index for such signals and channel conditions. It is shown that this equalizer algorithm, called the maximum likelihood equalizer, involves the iterative computation of one of the eigenvectors of a matrix. An implementation is proposed, which combines iterative estimation procedures for QR decomposition, matrix eigenvalue tracking and channel prediction error. Simulation results are presented that demonstrate the ability of the algorithm to equalize the channel filtering effects in a fast fading environment, without requiring phase coherent carrier recovery