Blind equalization for short burst communications over frequency selective wireless channels

Abstract

We investigate a blind equalization problem for short burst communications. Blind equalization becomes important for short burst communications, since training overhead can be significant when only a small number of bits are transmitted at a time. However, blind equalization has not been studied for cases where only a few bits are available in a burst for converging an adaptive blind equalizer. Several important points in applying blind equalization using constant modulus algorithm (CMA) to a short burst wireless communication have been identified. They include problems associated with convergence speed, ill convergence, short burst implications, dual mode operation, a fractionally spaced CMA equalizer and its initialization. Solutions to these problems are presented and incorporated in the algorithm. Simulations are performed using more than 4500 frequency-selectively fading channels. The results support the feasibility of the proposed algorithm.