MMSE-Based Block Implementation of Constant Modulus Algorithm

This paper introduces a new parallel scheme of Godard´s constant modulus algorithm which can be easily implemented by hardware. With the criterion of Godard´s constant modulus, stochastic gradient decency and block minimum mean square error, it realizes a parallel equalizer by adaptively adjusting the tap-weight vector. From numeric analysis and simulation, it is manifested that our scheme for quadrature phase-shift keying (QPSK) communication systems can achieve fast parallel equalization at the cost of less than 3 dB BER performance loss than the theoretic BER performance under low E_b/N_o (E_b/N_o is less than 10 dB) when the channel condition is rather severe. Therefore, it can be used to overcome the speed limitation of hardware for designing and implementing parallel blind equalizers especially in digital modems with high data rate.