Simple non-coherent detectors for CPM signals transmitted over Rayleigh flat-fading channels

We propose two novel non-coherent detection schemes for continuous phase modulated (CPM) signals transmitted over frequency-flat Rayleigh fading channels. These detectors are simple to implement and well-suited for the DIIS (Digital Interchange of Information and Signaling) system, an emerging new protocol for narrowband personal mobile radio promoted by the European Telecommunications Standard Institute (ETSI). The first scheme employs a phase detector followed by a matched filter and a Viterbi processor to perform sequence detection. The second scheme makes symbol-by-symbol detection and replaces the Viterbi processor with a linear equalizer and a threshold detector. Computer simulations are used to assess the performance of the proposed receivers. Compared with other existing methods, it is shown that significant complexity reduction can be achieved without incurring severe performance degradations.