中文说明：实现gps卫星的跟踪功能。载波跟踪环采用锁频环辅助下的锁相环，码跟踪环采用延迟锁相环。
English Description：
The tracking function of GPS satellite is realized. The carrier tracking loop uses the phase-locked loop assisted by the frequency locked loop, and the code tracking loop uses the delay phase-locked loop.