一种模糊智能高动态GPS载波跟踪环路设计

摘要

In high dynamic circumstance, shift and frequency change rate on GPS carrier the movements of vehicle cause a large Doppler frequency signals , then the loss of carrier tracking would occur in the loop. In order to enhance the performance of GPS receiver for high dynamic applications, a novel carrier tracking loop incorporating a fuzzy logic controller is proposed in this paper. The steady-state tracking accuracy is also improved by the linear interpolation algorithm to overcome the quantization error and deadtime of the fuzzy controller. Simulation results demonstrate that the proposed carrier loop can not only track the dynamic of carrier quickly, but also improve the tracking accuracy.%载体的高动态运动使GPS载波信号存在很大的多普勒频移和频移变化率，极易导致载波环路的跟踪失锁。为了提高GPS接收机在高动态环境中的跟踪性能，设计了一种新的基于模糊控制的载波跟踪环路，在Costas锁相环的基础上引入模糊逻辑控制器，使环路能够快速跟踪载波信号的动态变化，并采用二维线性插值算法消除模糊控制器的量化误差和调节死区，从而改善环路的稳态跟踪精度。仿真结果表明，所设计的环路能够在保证跟踪精度的前提下，有效提高对GPS载波信号的动态跟踪能力。