Robustness to fractionally-spaced equalizer length using the constant modulus criterion

This correspondence studies robustness properties of the constant modulus (CM) criterion and the constant modulus algorithm (CMA) to the suboptimal but practical situation where the number of fractionally spaced equalizer coefficients is less than what is needed to remove all intersymbol interference (ISI). Hence, there necessarily exists an error in the equalized signal. Relationships between CM and mean squared error cost functions are established.