SNR Estimation for a Non-Coherent M-FSK Receiver in a Rayleigh Fading Environment

This paper deals with the problem of estimating average signal-to-noise ratio (SNR) for a communication system employing non-coherent M-ary frequency shift keying (NCMFSK) over fading channels and white Gaussian noise (AWGN). We derive two estimators; one using maximum likelihood (ML) approach and other using the data statistics. Various scenarios have been taken into account including data-aided (DA), non-data aided (NDA) and joint estimation using both the data and pilot sequences. We also derive the Cramer-Rao bound (CRB) for the estimators. The results show that for a particular region of interest (e.g. high SNR or low SNR) and depending upon the availability of pilot sequence, a particular SNR estimation scheme is suitable.