Multichannel maximum-likelihood sequence estimation (MLSE) equalizer for GSM using a parametric channel model

In this paper, we propose a novel algorithm for the maximum-likelihood sequ ence estimation (MLSE) equalizer for the Global System for Mobile Communica tions (GSM) system. Specifically, we use a parametric model for the channel , along with a modified phase pulse-shaping function of Gaussian minimum sh ift keying (GMSK) modulation to obtain the modified Viterbi equalizer which we refer to as the parametric channel-Viterbi equalizer (PC-VE), In contra st to the conventional Viterbi equalizer with a finite impulse response (FI R) channel description, the PC-VE avoids the linear approximation error. Th e PC-VE also has a lower computational complexity if the number of the prop agation paths is less than the number of the FIR channel taps multiplied by the number of antennas. The proposed algorithm is applicable to both singl e and multiantenna receivers. An analytical expression for the BER as a fun ction of the SNR, path delays, and path DOA's has been derived. Some simula tion results that illustrate the performance of the proposed algorithm are presented.