The united detection of weak MSK signal using Duffing oscillator and Stochastic resonance

Concerning the problem that the traditional method is not valid to demodulate the MSK signal, this article is the first time to use Duffing oscillator and Stochastic Resonance to demodulate the MSK signal, a new demodulation method was proposed in this article. First, we put the MSK´s frequency compressed into a low range; then, we put the MSK signal into the Stochastic Resonance system to increase its SNR; later, we use the STFT to detect every code element´s signal´s frequency; finally, the decision device recovers the binary data according to this frequency. In this article, the power spectral entropy and the symbol demarcation point searching device are also the first time be introduced. The MATLAB simulation results show that this method can successfully demodulate the MSK signal, its minimum SNR is in -26dB.