Continuous phase frequency shift keying (CPFSK) is potentially an attractive modulation scheme for use on channels whose performance is limited by thermal noise. In this paper results for the performance available with CPFSK are given for coherent detection and noncoherent detection with arbitrary modulation indices and arbitrary observation intervals.
This work serves two purposes. First, it provides interesting, new results for the noncoherent detection of CPFSK which indicate that the performance of such a system can be better than the performance of coherent PSK. Secondly, it provides a complete analysis of the performance of CPFSK at high SNR as well as low SNR and thereby unifies and extends the results previously available.
Osborne, William P. and Luntz, Michael B. "Coherent and Noncoherent Detection of CPFSK." (Aug 1974).