基于SG-TDOA分区方案卫星随机接入能力分析

Analysis on Satellite Random Access Capability Based on SG-TDOA Grouping Scheme

针对GEO卫星通信系统随机接入碰撞概率高、往返时延大等问题,提出了一种基于SG-TDOA分区的方案,通过等时延差线对地面波束覆盖小区进行分区,利用覆盖用户的两颗卫星协同定位,获取用户终端的分区位置信息并对往返时延进行补偿,增大随机接入前导集,增强随机接入能力。仿真结果表明:与传统卫星随机接入方案相比,所提出的方案在随机接入能力方面有很大的改进,同时可以降低随机接入的碰撞概率。

Considering the high random access collision probability and large round trip delay in GEO satellite communication systems, a SG-TDOA grouping scheme is proposed. By portioning terrestrial cells based on the contour of propagation delay and cooperative positioning based on two satellites covering the user, the location information of the user terminal is obtained and the round trip delay is compensated to extend the random access preamble set and enhance the random access capability. Simulation results show that compared with the conventional satellite random access schemes, the proposed scheme not only highly improves the random access capability, but also reduces the random access collision probability.