A carrier frequency estimation algorithm for Multi-h CPM signals

Considering the problem that Multi-h CPM signal transmission performance is excellent but carrier frequency synchronization is complex, the article proposed a multi-h CPM non-data assisted carrier frequency estimation algorithm based on maximum likelihood. Firstly, the importance of carrier frequency synchronization is explained by simulating the influence of carrier frequency offset on transmission error performance. Then, the carrier phase deviation, frequency deviation, propagation delay, modulation index error and symbol error joint likelihood function in signal transmission are given. The likelihood function is derived and the maximum likelihood carrier frequency estimation is derived in detail. Then the flow chart of the carrier frequency synchronization algorithm based on maximum likelihood is designed. Finally, the ARTM Tier2 signal is simulated by Matlab simulation. The results show that the proposed algorithm is suitable for Multi-h CPM signals and has good carrier frequency estimation performance, and is insensitive to symbol timing deviation and modulation index synchronization error.