单载波干扰对星载扩频应答机码跟踪回路影响研究

扩频码同步是基于扩频体制卫星测控通信中的一项关键技术。研究单载波对星载扩频应答机中全时间超前-滞后非相干跟踪回路的影响，分析单载波干扰存在时跟踪抖动的恶化程度，给出相应的数学表达式，并进行了Matlab仿真。仿真结果表明：在一定的跟踪回路带宽下，恶化程度随着系统的扩频增益或频偏的增加而减小，并随着干信比的增加而增加。单载波干扰不变的前提下，恶化程度随着回路带宽的增加而增加。

Research on Effects of Single Carrier Interference on Satellite Spread-spectrum Transponder Code Tracking Loop

Synchronization of PN code is a key technology of satellite TT＆C communication based on spread spectrum system. The effects of single carrier interference on full-time lead - lag non-coherent tracking loop of spread-spectrum transponder was studied, the deterioration of tracking jitter where single carrier interference existed was analyzed and the corresponding mathematical expressions was given. Then the matlab simulation was conducted. Simulation results showed that deterioration of the tracking jitter decreased with the increase of the spread spectrum gain or frequency deviation and the deterioration increased with the increase of the interference signal ratio in certain loop bandwith. In the same premise of single carrier interference, deterioration of tracking jitter increased with the in- crease of the loop bandwith.