Digital Demodulation Algorithm Design and DSP Realization of Audio MFSK Signal

This paper designs a kind of noncoherent digital demodulation algorithm adapted to all-digital receivers according to the characteristics of M-ary digital frequency modulated MFSK audio frequency signal.The algorithm mainly includes the digital filter,digital frequency conversion,instantaneous phase,instantaneous frequency,median filter,decimation filter and timing recovery loop.The paper puts emphasis on the method of timing recovery loop aimed at the multi-level baseband of MFSK signal,and explains the questions to be noted in demodulation,and introduces the realization of the algorithm by DSP hardware platform after simulating the performance of the demodulation.