动态环境下载波锁相跟踪环的信号级仿真

在接收信号载噪比一定的前提下,针对GPS软件接收机在不同运动状态下载波环跟踪的问题,仿真研究了不同环路的跟踪性能:在低加速度动态下采用2阶锁相环跟踪更佳,在高加速度动态下则应该采用3阶锁相环跟踪。通过仿真验证了环路的有效性。此外通过仿真发现当载噪比和滤波器噪声带宽一定的情况下,选择合适的预检测积分时间可以有利于载波跟踪。

Signal Simulation on Carrier Phase-locked Loops in Dynamic Environments

With given carrier-to-noise ratio,and with regard to GPS software receiver carrier loop tracking in different dynamic environments,different loops’ tracking performances are simulated and studied.A second-order phase-locked-loop is adopted for the low acceleration-dynamic signal,whereas a third-order phase-locked-loop is adopted for the high acceleration-dynamic signal.The simulation proves the effectiveness of the loops,and it also proves that a properly selected pre-detection integration time is helpful for carrier tracking when the signal’s carrier-to-noise ratio and filter noise-band are given.