Decision directed algorithms for blind equalization based on constant modulus criteria

Abstract

A family of techniques aiming to perform blind equalization for Quadrature Amplitude Modulation (QAM) signals is presented. The proposed algorithms are decision directed and based on modi ed Constant Modulus (CM) criteria. Two approaches are used to develop the algorithms: the Stochastic Gradient Descent approach and the Normalized Constant Modulus Algorithm (NCMA) approach. Computer simulations con rm the expected results and show that the proposed algorithms outperform the conventional CM based algorithms.