基于TDOA/FDOA相位条纹的高精度GPS信号跟踪方法

High-precision GPS Signal Tracking Method Based on TDOA/FDOA Phase Stripe

针对传统GPS接收机跟踪环路结构复杂,以及在低信噪比(SNR)、高动态条件下跟踪性能较差的问题,该文提出一种基于相位条纹斜率检测的跟踪新方法。通过采用到达时差(TDOA)的频域相位测量伪码时延,到达频差(FDOA)的时域相位测量载波多普勒频偏。该方法降低了环路实现的复杂度,同时提高了跟踪精度。仿真结果验证了该方法的有效性和稳定性,在载噪比为32 dB-Hz时,相比传统方法,基于TDOA/FDOA相位条纹法的码相位测量精度提高了60%,载波多普勒测量精度提高了31%,且在高动态环境中也能实现精确跟踪,对改善GPS接收机跟踪性能具有研究意义。

In order to solve the problems of complex tracking loop structure of traditional GPS receivers,and poor tracking performance in the environment of low Signal-to-Noise Ratio(SNR)and high dynamic,a new GPS signal tracking algorithm based on phase slope stripe detection is proposed,in which the pseudo-code delay can be accurately estimated by the Frequency domain phase of Time Difference Of Arrival(TDOA),and the carrier Doppler frequency offset can be accurately estimated by the Time domain phase of Frequency Difference Of Arrival(FDOA).The loop structure is simplified and the tracking accuracy is improved,compared with the traditional method,the code phase measurement accuracy is improved by 60%and the carrier Doppler measurement accuracy is improved by 31%when the SCNR is 32 dB-Hz.In addition,accurate tracking can be achieved in high dynamic environment,which has research significance for improving the performance of GPS receiver.