Analysis of the multimodulus blind equalization algorithm for non-square rectangular QAM signal constellations

This work mathematically analyzes a multimodulus blind equalization algorithm (MMA) for non-square rectangular quadrature amplitude modulation (QAM) signal constellations. The analysis indicates that the MMA that uses non-square rectangular constellations may be better able to recover the phase rotation introduced by channels than the MMA that uses either the square or the cross constellations, although the former is known to require more average transmitted power than the latter two. The analysis also demonstrates that the MMA that uses non-square rectangular constellations may be less attracted to saddle points (thus increasing convergence speed) than the MMA that uses cross constellations, because the former has fewer saddle points than the latter.