基于I/Q支路相干积分观测滤波的GPS接收机信号跟踪方法

针对传统GPS接收机在弱信号环境下跟踪误差大，收敛速度慢的缺点，该文提出一种基于I/Q支路相干积分观测滤波的GPS信号跟踪方法。将接收机I/Q支路相干积分输出为观测量，应用无迹卡尔曼滤波(Unscented Kalman Filter, UKF)算法构建卡尔曼滤波器，得到基带数字信号处理滤波模型，闭合接收机跟踪环路。该方法能够有效减小传统GPS跟踪环路中信号参数的估计误差，提高接收机抗干扰能力和弱信号环境下环路跟踪性能。仿真对比结果表明，不同载噪比环境下相比传统GPS信号跟踪的方法，基于I/Q支路相干积分观测的信号跟踪算法能够提高跟踪精度，加快跟踪收敛速度。

GPS Receiver Signal Tracking Method Based on I/Q Branch Coherent Integration Measurements Filter

Due to the disadvantages of a traditional GPS receiver in the environment of weak signal are that slow convergence rate and serious tracking error, a GPS signal tracking algorithm is proposed, in which the coherent integration of I/Q branch is considered as measurement of Unscented Kalman Filter (UKF). The filter model of the baseband signal processing is constructed and tracking loop is closed by UKF. Then the signal parameters of GPS tracking loop can be accurately estimated. Moreover, the anti-jamming capability and tracking ability of receiver are improved in the presence of weak signals. Simulation results demonstrate that the tracking ability and convergence rate of proposed algorithm outperform traditional method in the case of different Carrier to Noise ratio (C/N).