Signal Capture and Tracking in Inter-Satellite-Link Communication Based on CAZAC Sequences

With various countries and companies vigorously advancing satellite communication, dense satellite constellations deployed in low Earth orbit (LEO) will play a significant role in wireless communication in the near future. Moreover, the 3rd Generation Partnership Project (3GPP) is striving to integrate satellites into 5G and beyond-5G networks. However, harnessing the connectivity potential of satellite constellations necessitates overcoming several challenges. These challenges mainly stem from the short duration of passage of low Earth orbit satellites, the limited capacity of individual small satellites, and their restricted coverage area. Consequently, the stability of intersatellite links(ISLs) becomes particularly vital.In ISL communication, precise signal acquisition and tracking are pivotal to ensuring reliable signal transmission and reception. In this paper, we present a signal capture and tracking method based on CAZAC sequences. By leveraging the autocorrelation property of CAZAC sequences, accurate signal timing and synchronization can be achieved, thus enhancing signal detection efficiency in complex ISL environments. We confirm that CAZAC-based ISL communication is comparable in performance to mature GPSbased ISL communication technologies. This approach effectively mitigates interference and enhances spectral efficiency in multicarrier systems.