GPS软件接收机载波跟踪环路鲁棒滤波算法

在全球定位系统(GPS)软件接收机中,环路滤波器对噪声抖动的抑制作用,是用户精确连续跟踪卫星信号的重要保证.本文用噪声未知但有界的假设,代替了传统方法中噪声统计特性已知的苛刻要求,应用半定规划方法将滤波问题转化为凸优化问题,提出了载波跟踪环路鲁棒滤波算法,获得了包含多普勒频移的置信椭球,解决了复杂多变环境下GPS软件接收机的滤波跟踪问题.应用模拟载波信号和实际卫星信号对该算法进行验证,结果表明该方法能够连续有效跟踪GPS卫星信号,为GPS软件接收机设计环路滤波器提供了新的思路.

Robust filter algorithm of carrier tracking loop for GPS software receiver

The inhibition of the loop filter noise jitter is an important guarantee for precise continuous tracking of the satellite signal in global positioning system (GPS) software receiver. This paper uses the noise unknown but bounded assumptions, instead of the demanding requirements of the noise statistical properties known in the traditional methods. The application of semidefinite programming approach converts the filtering problem into a convex optimization problem. Adopting the carrier tracking loop robust filtering algorithm to obtain the confidence ellipsoid containing the Doppler shift, we solve the filter tracking problem for GPS receiver in the complex and changing environment. The algorithm is validated by using the analog carrier signal and the actual satellite signal. Results show this method effectively tracks the GPS satellite signals and provides a new way of thinking for designing the loop filter for GPS receivers.