On the misconvergence of CMA blind equalizers in the reception of PN sequences

This paper presents an investigation of the misconvergence of the constant modulus algorithm (CMA) for blind equalization in the reception of M-ary PSK or QAM signals that are derived from encoding binary PN sequences. Formulas for the period and probability density-function (p.d.f.) of the pseudo-random M-ary sequence as functions of M and the period of the underlying binary PN sequence are given. The distortion of the probabilistic symmetry of the transmitted constellation is also quantified. Simulation results are presented that illustrate the influence of these signal characteristics on the convergence behavior of CMA.<<ETX>>