Multilevel Decision Method for Band-Limited Digital FM with Limiter-Discriminator Detection

A new decision method for band-limited digital FM that employs discriminator detection is presented. This new method adopts a multilevel decision scheme to soften the intersymbol interference effects caused by severe band limitation. It is shown that applying this method significantly improves bit error rate (BER) performance of digital FM using discriminator detection. Theoretical BER evaluation proves the superiority of this method, and establishes the optimum values for fundamental transmitter parameters. Experimental results are provided to support the superiority of this method.