Research on technology of multipath cross-band regenerative frequency coherent retransmission

To address the issue of ground stations being unable to directly communicate with user satellites and the inability to conduct direct two-way measurements, this paper describes the multi-path cross-band measurement regenerative frequency coherent retransmission technology suitable for the unified carrier system. By employing a frequency coherent retransmission error elimination method and designing coherent retransmission ratio factors between different bands, the coherence of regenerative frequency retransmission across multiple channels is ensured. This allows the transmit and receive frequencies in multi-path retransmission to satisfy the relationship of regenerative coherent retransmission, thereby enabling real-time positioning and orbit determination for user satellites. This method can also be combined and designed according to different application scenarios and frequency band requirements. Theoretical analysis and simulation results demonstrate that this approach eliminates the impact of relay satellite clock errors on frequency coherent retransmission, ensures the coherence between multi-hop transmit and receive frequencies, and thus meets the requirement of a multi-hop velocity measurement error of less than 0.1 mm/s(ECSS-E-50-02A), showing promising prospects for engineering applications.