Maximum-Likelihood-Based Frequency Synchronizer for Dual-H Full- Response 4-ARY Continuous-Phase Modulation (CPM)

摘要

Maximum-likelihood techniques are useful in finding structures for synchronizers for various cases. Synchronizers for frequency, phase, and timing have been found for various bandpass signaling techniques such as PSK, DPSK, QAM, MSK, and CPM. These include data-aided, decision-directed, clock-aided cases. For Continuous-Phase Modulation (CPM), however, apparently only the single modulation index case has ML-based synchronizers. This report describes a new non-data-aided, non-decision-directed ML-based frequency synchronizer (with no phase or timing information) derived for a full-response, dual-h (two modulation indexes), 4-ary CPM signaling scheme. The derived structure will be incorporated into future simulations to compare performance among several possible frequency synchronizers.