Improving the performance of the error function for fast phase recovery of QAM signals in CMA blind equalizers using variable step
Sathyanarayan S. Rao, Priyadarshini Muddepal, Sudarshan R. Nelatury · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2004
A new constant modulus algorithm (CMA) type of error function for fast phase recovery of QAM signals was recently proposed in which the cost function of the error function recovers the phase simultaneously with the equalization. In this paper we propose variable step (VS) in the update equations of new error function to enhance the performance of convergence speed and residual inter-symbol interference (ISI). Effectiveness of the error function for well-behaved channel, under-modeled channel and channel disparity are presented. Simulation results are presented to compare the performance of VS, constant step (CS) and the modified CMA (MCMA) using 16-QAM signal constellation.