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 bu t practical situation where the number of fractionally spaced equalizer coe fficients is less than what is needed to remove all intersymbol interferenc e (ISI), Hence, there necessarily exists an error in the equalized signal. Relationships between Chi and mean squared error cost functions are establi shed.