Fading in mobile GMSK

A new receiver structure was previously proposed for decoding GMSK. The decoding algorithm was developed using the reference-probability-method for hidden Markov models. This receiver was shown to be insensitive to the levels of the intersymbol interference which result when the out-of-channel power spectral density is reduced, but the effect of fading was ignored in the analysis. This paper extends the earlier work and shows that similar design methods can be used to derive a receiver algorithm having reduced sensitivity to signal attenuation. A nonlinear, multisample decoder is presented which has an improved detection probability in the presence of dynamic fading.