电离层闪烁下4路信号处理的载波锁相环

针对电离层闪烁导致的卫星导航接收机载波锁相环失锁问题，提出一种基于Kalman滤波器的4路信号处理载波锁相环. 该环路通过增加两路信号处理对锁相结果进行纠正，扩大了锁相环的相位牵引范围，同时根据信号实时载噪比自适应调节滤波系数，有效避免电离层闪烁时信号振幅衰落和相位突变引起的环路失锁. 通过仿真表明，这种锁相环可以在持续中强度和瞬时高强度的电离层闪烁下保持跟踪. 

Four-Way Signal Processing Carrier Phase Lock Loop in Ionosphere Scintillation Environment

A Kalman filter was proposed to solve loss of lock in ionosphere scintillation environment based on four-way signal processing carrier phase locked loop (quad-PLL). Extra two ways signal was added to correct phase discriminator's output with purpose of expanding phase pull-in range, while filter parameters were adjusted adoptively according to real-time carrier to signal ratio. Loss of lock was avoided effectively when amplitude fading and phase mutation were caused by ionosphere scintillation occurs. The simulation result shows that this proposed PLL can keep tracking in the high-intensity strength and instantaneous ionosphere scintillation.