Performance analysis of narrowband digital PM demodulator with zero-crossing postprocessors

A baseband receiver, called zero-intermediate frequency zero-crossing demodulator (ZIFZCD), was previously developed for implementation of a narrowband digital FM receiver. The ZIFZCD offers increased battery life and simpler implementation. However, the bit error rate (BER) performance of the ZIFZCD is inferior to those of conventional schemes. Two postprocessors, a sliding window (SW) and a decision feedback (DF), are employed to improve BER performance of the ZIFZCD. The objective of this paper is to analyze the BER performance of the ZIFZCD with SW and DF postprocessors for minimum shift keying signaling under static environment. An approximation of the BER performance of the ZIFZCD with a SW is presented. In addition, an exact BER of the ZIFZCD with a DF is studied, The analyzed BER results agree well with the simulated ones and show significant BER improvement by employing SW and DF postprocessors.