Abstract:Timing synchronization with the early/late loop scheme based on sequence detection was proposed for multi-h continuous phase modulation. The timing error detector was implemented by the survival metrics of Viterbi algorithm. The so-called S-curve and estimation variance were used for optimizing the acquisition range and tracking performance as well as eliminating false lock points of the loop. Using the PAM (pulse amplitude modulation) representation of multi-h CPM(continuous phase modulation), the proposed timing error detector is simplified. Simulation results show that the estimation range is as large as ±0.5 symbol period, and estimation precision is close to the modified Cramer-Rao bound at medium and low SNR(signal noise ratio), and it also has better estimation performance at high SNR. BER (bit error rate) with simplified schemes are derived. It is demonstrated that when the number of Viterbi metrics is reduced to 1/8 of the maximum likelihood sequence detection, the performance loss is only less than 0.5 dB for Mary or partial response of multi-h CPM.