Abstract
We examine the behavior of the leaky constant modulus algorithm (L-CMA), which is a special case of the recently proposed minimum equalizer norm constant modulus algorithm (MEN-CMA). LCMA is shown to minimize a combination of the intersymbol interference (ISI) introduced by the channel and the noise amplification factor of the equalizer. Some local minima of the standard (MA cost function that cause large noise amplification for a fractionally spaced equalizer can be eliminated. We also identify a class of channels for which L-CMA performs poorly as a consequence of the minima of the L-CMA cost function forming in the neighborhood of certain saddle points of the CMA cost function, particularly when the eigenvalue spread increases. This contradicts the conventional thinking that the performance advantage of L-CMA will improve with increased eigenvalue spread of the channel. © 1999 IEEE.