Near-Optimal Low Complexity MLSE Equalization

An iterative maximum likelihood sequence estimation (MLSE) equalizer (detector) with hard outputs, that has a computational complexity quadratic in the data block and the channel length, is proposed. Its performance is compared to the Viterbi MLSE algorithm that has a computational complexity that is linear in the block length and exponential in the channel memory length. It is shown via computer simulation that the proposed iterative MLSE detector is able to detect binary phase-shift keying (BPSK) signals in systems with significantly larger channel length than what is possible with the Viterbi algorithm, for frequency selective Rayleigh fading channels.