A Simplified Direct-Decision Synchronization Algorithm for Coherent CPM Receiver Using Linear Phase Approximation

We propose a simplified decision-directed synchronization algorithm for continuous phase modulation (CPM) based on the linear approximation to the phase of the CPM signal. It yields simple and practical synchronization algorithm with closed-loop architecture, in which the derivative matched filters are not required. Numerical results demonstrate that this novel synchronizer achieves improved timing estimation performance while requiring lower complexity when compared with the well-known method based on pulse amplitude modulation approximation. The demodulation architecture with the proposed algorithm is presented, and its bit-error-rate approaches the theoretical bound.