Polar Code-Aided Frequency Offset Estimation Algorithm in Satellite Covert Communication Carrier Synchronization

At present, covert satellite communication has become one of the most important application scenarios in the communication field. Due to various interferences and detections in space communication environment, satellite covert communications usually adopt short codes for channel coding, such as polar codes. However, polar coding method is highly sensitive to carrier synchronization error, and the performance of the satellite covert communication will degrade severely with the presence of carrier frequency offset. Therefore, carrier synchronization is a critical issue in the field of covert satellite communication. Existing carrier synchronization algorithms are mostly based on pilot assistance and have low spectrum utilization. To cope with the challenge of limit of spectrum in satellite communication and at the same time to guarantee a high communication quality, we propose a polar code-aided frequency offset estimation (PCAFOE) algorithm model in this paper. Based on the estimation indicator of RMSE, Monte Carlo simulations and corresponding analysis are presented. Compared with the traditional carrier synchronization algorithm, PCAFOE algorithm is demonstrated with higher estimation accuracy, which is able to effectively improve the carrier synchronization performance of covert satellite communication systems.