A new blind equalization structure for deep-null communication channels

We propose a new blind equalization structure that is well suited for communication channels characterized by deep spectral nulls and that directly estimates the channel coefficients. Blind equalization of communication channels has increasing importance, due to the need to maximize bandwidth efficiency. Established Bussgang algorithms applied to finite impulse response (FIR) structure equalizers perform poorly when one or more maximum phase zero of the channel is close to the unit circle. This limitation is due to the difficulty of modeling the inverse of the maximum phase component of the channel with a finite length FIR filter. Theoretical analysis and simulation studies support the potential of the new structure to model the required inverse entirely and, hence, to equalize such difficult channels