Joint Carrier Synchronization Algorithm by Open-Loop Acquisition and Closed-Loop Tracking in High-Dynamic Environments

Abstract

Considering the difficulty of carrier synchronization and the low tracking accuracy in high-dynamic environments, the joint open-loop acquisition and closed-loop tracking carrier synchronization algorithm is presented. Firstly, the algorithm derives the coarse estimation of Doppler frequency and Doppler rate via open-loop acquisition, then the residual Doppler frequency and Doppler rate are confined into a small range. Secondly, the residual Doppler rate is tracked by using a third-order phase-locked loop(PLL). The present algorithm has the advantages of fast acquisition and high tracking accuracy. Finally, the numerical simulation is conducted to verify the present synchronization algorithm. The simulation results indicate that at the signal to noise ratio(SNR) of and normalized Doppler frequency and Doppler rate ranging from to, the bit-error-rate(BER) performance degradation is as low as comparing with theoretical value.