A novel re-initialization technique for CMA in the presence of channel noise

The error surface associated with the constant modulus algorithm (CMA) is multimodel. Therefore, an equalizer adapted with CMA has the potential to converge to a local minimum that has large noise amplification. A technique is, therefore, proposed based upon a solution of linear and quadratic equations to re-initialise the equalizer parameters. Linear equations are obtained from the fact that the retrieved transmitted signal with various delays which correspond to different minima are uncorrelated. The quadratic equations are obtained from the knowledge of the transmitted signal power. Simulations are included to demonstrate the robustness of this new scheme.