关键词: 激光星间链路, GNSS, 混合星间链路, 遗传算法, 粒子群优化

Abstract:

With the development of inter-satellite link technology， laser inter-satellite links have garnered widespread attention due to its unique advantages. Compared to the current Global Navigation Satellite System （GNSS） that uses microwave inter-satellite links， laser-based inter-satellite communication offers advantages in terms of both ranging accu racy and communication bandwidth. Consequently， the network configuration of the next-generation GNSS will transition from relying entirely on microwave inter-satellite links to primarily using laser inter-satellite links. However， during the transition phase， where both laser and microwave links coexist， the deployment of high-speed laser nodes is a critical technical challenge that need to be addressed. To solve the challenge， this paper proposes a Multi-objective Discrete Binary Selection Algorithm （M-DBSA） based on the non-dominated sorting genetic algorithm with the elite strategy. Firstly， a high-medium-low inter-satellite visibility model is established based on analysis of inter-satellite geometric constraints and antenna elevation angle constraints. Secondly， to enhance the communication capability of inter-satellite links in hybrid GNSS， an optimized joint strategy is obtained using the M-DBSA algorithm. Finally， the experiment results demonstrate that compared to other algorithms， the proposed algorithm can further improve the coverage from laser backbone nodes to low-orbit satellites， shorten the high-speed laser backbone nodes’ revisit time of low-orbit satellites by about 49%， and maintain a better distribution of communication hops.

Key words: laser inter-satellite link? GNSS? hybrid inter-satellite link? genetic algorithm? particle swarm optimization