Modeling and simulation of FM detection by zero-crossing in the presence of noise and FH interference

A signal model for a frequency-hop (FH) spread spectrum system and an FM system is presented, and the demodulation of an FM signal in the presence of interfering FH and noise is described. The FM receiver presented uses a zero-crossing scheme for demodulation. To demonstrate the zero-crossing technique, two algorithms are developed and examined. The results show that for many applications, FM systems could reasonably coexist with frequency-hopping spread-spectrum systems. Furthermore, zero-crossing demodulation schemes are shown to be useful with microprocessor-based detector systems