An adaptive innovations-based MLSE receiver for frequency-flat correlated Rayleigh-fading channels

A modified version of innovations-based maximum likelihood sequence estimation (MLSE) receiver for M-PSK signals transmitted over a frequency nonselective Rayleigh-fading channel is proposed. The receiver structure suggested in this paper adopts the per-survivor processing (PSP) technique that is known as a powerful remedy in a slow to moderately time-varying unknown channel environment. The proposed scheme does not assume any statistical model of the fading process and knowledge of the variance of additive white Gaussian noise, but still shows robust detection performance over a wide range of maximum Doppler frequency shift without exhibiting the irreducible error floor at a high signal to noise ratio (SNR) region.