Asynchronous multiple-access interference suppression using variable block adaptive filtering in time-varying multipath channels

A computationally-efficient fuzzy-logic controlled block adaptive filtering (FLC-BAF) technique is developed for asynchronous DS-CDMA systems with antenna arrays in multipath Rayleigh-fading channels. This time-varying block filtering scheme employs a (2-to-1)-fuzzy inference system (FIS) to determine the processing blocksize Q. Consequently, this FLC-BAF approach accomplishes a substantial reduction of the computational cost without compromising bit-error-rate (BER) performance and dynamic-tracking characteristic. Simulations are conducted to illustrate the BER and convergence/tracking superiority and to provide a comparative evaluation of the proposed algorithm to other known block processing algorithms.