MSK Carrier Synchronization Scheme Based on Demodulation Soft Information Aided

The existing carrier synchronization algorithms for MSK signals suffer from the disadvantages of low estimation accuracy and difficult implementation under the condition of low signal-to-noise ratio (SNR). To address the problems, the paper proposes a novel carrier synchronization scheme based on demodulation soft information aided. The joint iteration of the synchronizer and demodulator aims to maximize the objective function, the mean square value of demodulation soft information. In the two-dimensional search of carrier frequency and phase offset, the scheme realizes carrier synchronization of near maximum likelihood estimation. It is shown, via analyses and simulations, that its bit error rate (BER) performance approaches the theoretical bound. This scheme is an effective solution for MSK short-time burst transmission systems at the expense of low complexity.