Dual Mode AVMA for Blind Equalization and Carrier Phase Recovery in Distorted Communication Channels

A modified version of adaptively varying modulus algorithm (AVMA) is presented: the dual mode adaptively varying modulus algorithm (DM/AVMA), which accomplishes blind equalization and carrier phase recovery simultaneously in case of distorted channels. The DM/AVMA first acts a standard MCMA and once the convergence to certain level is achieved, the AVMA comes into action to acquire the signal constellation toward the orientation of the source constellation. The whole operation is controlled by adjusting the coefficients of two gradient vectors for each cost function correspondingly. Simulations studies for the case of 16-QAM signal constellation confirm the effectiveness of the proposed algorithm in clustering the equalized signals, recovering and correcting the carrier phase shift and removing ISI in the presence of distorted communication channels