GEO卫星移动通信系统的多信关站同步技术

Synchronization Technology for Multiple Gateway Stations in GEO Satellite Mobile Communication System

对目前国外较为成熟的GEO卫星移动通信系统的多信关站同步技术进行了分析,并针对采用FDMA/TDMA体制的天通一号卫星移动通信系统,提出了基于主从方式的多信关站时频同步方案,使各从信关站同步到主信关站的时间基准上,同时各信关站根据卫星信标信号、环回的信关站帧参考(GFR)信号计算出卫星本振信号漂移和卫星多普勒漂移两个重要参数,获得对频偏的修正值,从而在不需要卫星发射载荷同步信号的情况下实现了多信关站在馈电链路上的同步。最后,采用地面模拟设备对星进行了无线试验验证,试验结果表明,该方法满足信关站的同步精度要求。

This paper analyzes the synchronization technology of multiple gateway stations in the GEO satellite mobile communication system overseas,and aiming at Tiantong satellite mobile communication system operating in FDMA/TDMA mode,proposes a time and frequency synchronization scheme of multiple gateway stations based on master-slave mode. This method synchronizes the slave gateway stations to the time reference of the master gateway station. At the same time,the two important parameters of satellite oscillator signal drift and satellite Doppler frequency drift are calculated according to satellite beacon signal and loopback gateway frame reference（ GFR） signal,and the correction value of the frequency offset is obtained,thus realizing the synchronization of the multiple gateway stations on the feeder link without the need of the satellite to send load synchronization signal.Finally,the wireless test of the satellite is carried out by the ground simulation equipment,and the test results show that the method can meet the synchronization precision demand of the gateway station.