Optimal/adaptive demodulation for M-ary FSK in fast fading

This work extends the analysis developed in a preceding report, of optimal demodulation for M-ary FSK waveforms that are corrupted by rapid signal scintillation fading and noise. The research documented here extends the original analysis to incorporate estimation algorithms for signal spectral spreading. This new receiver design adapts to channel conditions and is called the optimal/adaptive demodulator. The optimal/adaptive demodulator operates like the optimal receiver previously documented except that it also forms the necessary spectral estimates of the received signal plus noise. The new design remains optimal, in the sense of minimum probability of error, in steady signal and slow fading conditions while providing successful performance in much faster fading conditions than possible with conventional receivers. The mathematical development, design and performance of the new optimal/adaptive demodulator are documented in this work.