基于双码时延间隔的GNSS矢量跟踪环路

The GNSS Vector Tracking Loop Based on Double-code Delay Interval

针对传统GNSS接收机在弱信号下工作性能不理想的特点,分析了传统接收机和矢量接收机的工作原理,归纳总结了传统接收机在弱信号下的性能缺陷;在弱信号下对比传统标量接收机与矢量接收机的跟踪性能,提出用设置双码时延间隔的方法来优化矢量跟踪性能。用矢量跟踪来弥补传统接收机在弱信号下的缺陷。仿真结果表明:在载噪比15～22dB情况下,采用双码时延间隔EKF算法的矢量接收机跟踪性能要优于传统标量接收机,且比采用单码时延间隔的矢量接收机码跟踪误差还要小约20ns。

According to the condition that the operating performance of the traditional GNSS receiver is not ideal in the weak signal environment, firstly the article analyzes the working principle of traditional receiver and vector receiver, summarizes the traditional receiver＇s performance deficiency in the weak signal envi ronment, secondly the tracking performance of the traditional scalar receiver and that of the vector receiver are compared in the weak signal environment, and simultaneously the method of setting up the delay inter- val of double-code is put forward to optimize the vector tracking performance. The technology of vector tracking is used to make up for the defect of traditional receiver in the weak signal. The experimental re sults show that the double-code delay interval vector receiver which uses EKF algorithm is superior to the traditional scalar receiver in tracking performance in the condition that the carrier-to-noise ratio is 15-22 dB/Hz, and its tracking error is about 20 ns smaller than the tracking error of the one-code delay interval vector receiver.