The Performance Of Optimized Carrier Tracking Loop In Weak Signal

Stable carrier tracking is a hard problem in weak signal receiver. Digital Costas Loop is usually used, which is analysed using analog phase lock loop method in traditional condition. Since the existence of high order dynamic parameters, the update rate of the loop will also affect the weak signal tracking performance. If user is almost static or in very low acceleration, the longer integration will be work well, if a terminal is in high dynamic, the longer integration will depress the dynamic property. There's no update rate in traditional analog phase lock loop. In order to optimize the coefficients in digital Costas Loop including the integration time, an algorithm based on the steady state of kalman filter is introduced.