Concurrent Blind Channel Equalization in Impulsive Noise Environments

In some communication systems the transmitted signal is contaminated by impulsive noise with a non-Gaussian distribution. Non-Gaussian noise caused significant performance degradation to communication receivers. The new constant modulus blind equalizer based on Fractional lower-order statistics of the equalizer input, which is defined as FLOS_CMA, is able to mitigate impulsive channel noise while restoring the constant modulus character of the transmitted communication signal. However, like the Constant modulus algorithm (CMA), the steady-state Mean square error (MSE) of the FLOS_CMA algorithm may not be sufficient low for the system to obtain adequate performance. This paper proposes a concurrent equalizer, in which a Decision-directed least mean p norm (DD_LMP) equalizer operates cooperatively with a FLOS_CMA equalizer, controlled through a non-linear link. Simulation results using M-QAM and 8-PSK signaling have shown that besides the capability of compensating the phase offset, the proposed concurrent FLOS_CMA and DD_LMP blind equalizer has faster convergence rate and lower steady-state MSE than the FLOS_CMA approach.