Blind equalization based on radius directed adaptation

A blind equalization algorithm, termed radius directed equalization (RDE), for quadrature amplitude modulation (QAM) signals based on the known modulus of the constellation symbol radii is described. For example, 16 QAM has three radii and 32 QAM has five radii. The algorithm uses the error between the equalizer output modulus and the nearest symbol radius to update the equalizer weights. The RDE algorithm provides faster convergence than the constant modulus algorithm (CMA) for QAM signals and is independent of the carrier offset. The algorithm is described in the context of blind carrier and baud clock recovery schemes.<>