Performance analysis of GMSK discriminator integrator detection with decision feedback equalization in land mobile radio channel

GMSK is an FM digital modulation of great interest in mobile communications because of its compact power spectrum and constant envelope property. Simple noncoherent detectors for reception of GMSK signal, as a limiter-discriminator or a limiter-discriminator followed by 1-bit or 2-bit integrate-and-dump postdetection filtering, are considered. The numerical and simulation results show that decision feedback equalization improves the bit error rate (BER) performance in fast fading channels not only in the lower range of the signal-to-noise ratio, but also in the irreducible error floor due to the Doppler shift. The effect of the variation of the integrate-and-dump filter integration time is also investigated, in order to optimize the BER performance in a land mobile channel.