Normalized adaptive decision directed equalization

It has been observed that with appropriate stepsize normalization, the convergence speed of the constant modulus (CM) algorithm can be dramatically improved. It is shown that if a different normalization strategy is used, one that takes into account the finite alphabet structure of the signals, a standard normalized version of the decision directed equalizer (DDE) is achieved. A simulation example is included to demonstrate the faster convergence of the normalized DDE compared with its constant stepsize implementation and the normalized CM.