INS/GPS紧组合系统PLL最优带宽的选取

在INS/GPS紧组合系统中,通过INS提供的多普勒辅助信息可以消除GPS跟踪环路的动态性,同时降低环路带宽来抑制热噪声的影响,从而提高GPS系统的抗干扰能力。环路带宽是跟踪环路的一个重要参数,不能任意选取,当GPS跟踪环路设置为最优带宽时,系统性能将达到最优状态。为了保持系统性能最优,首先对影响最优带宽的各个误差源进行分析,提出了易于实现的迭代最优带宽算法,最后进行了仿真实验验证,结果表明在相同动态下采用最优带宽比固定带宽的系统具有更高的抗干扰能力和更强的跟踪锁定性能。

PLL optimal bandwidth selection in INS/GPS tight integration system

In the Inertial Navigation System/Global Positioning System(INS/GPS) tight integration system, Doppler aided GPS Phase Locked Loop(PLL) information provided by INS can eliminate system dynamic and also reduce the tracking loop bandwidth to suppress thermal noise, thereby improving GPS anti-jamming capability. The bandwidth is an important parameter of tracking loop and cannot be selected arbitrarily. When the GPS tracking loop bandwidth is set to the optimum, the GPS performance can reach the optimal state. In order to maintain optimal system performance, firstly, the factors influencing the optimal bandwidth selection are described; secondly,iterative algorithm is proposed which is easy to achieve optimal bandwidth.Experimental results show that the system adopting the optimal bandwidth has higher anti-jamming capability and stronger tracking-locking performance than the system adopting fixed bandwidth in the same dynamic.