An Adaptive Demodulation Method for MFSK Signals under Alpha-Stable Distribution Pulse Noise

Pulse noise in many practical occasions can be modeled as alpha-stable distribution noise. Communication systems often work under this noise background. A new adaptive demodulation method for M-ary frequency-shift keying (MFSK) signals under alpha-stable distribution pulse noise is proposed. To track single frequency of any code interval of signal to demodulate MFSK signals, the normalized least mean p-norm adaptive filtering algorithm is used. The simulation results indicate that this adaptive demodulation method can demodulate 2FSK and 4FSK very well under alpha-stable distribution pulse noise. When SNR is above 11 dB, the symbol error rate (SER) of the proposed adaptive demodulation method for 2FSK is below 8 times 10^-4, and when SNR is above 14 dB, the SER for 4FSK is below 10^-3 . And this method also works well under Gaussian noise. The performance of the proposed adaptive demodulation method is much better than that of coherent demodulation method. And this method is very easy to implement.