Decision feedback postprocessor for zero-crossing digital FM demodulator

A baseband digital narrow-band FM receiver, called zero-intermediate freque ncy zero-crossing demodulator (ZIFZCD), has been recently developed. This d emodulator may offer low complexity and simple implementation. However, the bit error rate (BER) performance of the ZIFZCD is inferior to that of the limiter-discriminator-integrate-and-dump (LDI) demodulator, In this paper, a simple decision feedback postprocessor (DFP) is proposed to improve the p erformance of the ZIFZCD. Analysis and simulation BER results of the ZIFZCD with the DFP are presented for minimum-shift keying (MSK) and Gaussian MSK (GMSK) signals under additive white Gaussian noise (AWGN) and mobile fadin g environments.