Non-Linear Equalization for Incoherent Radiomobile Channel

This paper presents the simulation study of a multiple-symbols differential demodulator for Gaussian Minimum Shift Keying (GMSK) which compensates for the heavy selective distortions caused by multipath propagation. The receiver includes a channel estimator operating in a training mode at the beginning of each burst, and a multiple-symbols differential processor which has been demonstrated in the literature to be optimum over non-coherent AWGN channels. The combination of channel estimation and differential demodulation makes the receiver robust to fast Doppler shifts and to wide time-spread. Simulation results are presented which show the performance in different multipath environments based on the recommendations established by the GSM system. Comparisons with a coherent receiver including a matched filter, an adaptive channel estimator and a Viterbi processor show that the detector proposed in this correspondence is quite attractive.