SNR Estimation for Non-Coherent M-FSK Receivers in Rice Fading Environment

The problem of estimating the average signal-to-noise ratio (SNR) in a non-coherent M-ary frequency shift keying (NCMFSK) receiver has been considered, where the transmitted signal is propagated over a noisy Ricean fading channel. Closed-form maximum likelihood estimators for both the data-aided and non data-aided scenarios have been derived using the approximations of the modified Bessel functions. Numerical results are presented and the performance of the estimators is evaluated by comparing with a Cramer-Rao bound.