Leaky constant modulus algorithms: sensitivity of local minima

We propose a new family of mixed constant modulus algorithms for the elimination of local minima associated with the fractionally spaced constant modulus algorithm in the presence of channel noise. A special case of this family is the leaky constant modulus algorithm (L-CMA). We show that L-CMA aims to minimise jointly the intersymbol interference (ISI) and the noise gain introduced by the equalizer. Moreover, we derive a suitable range of leakage factors for which all local minima due to large noise amplification are eliminated