采用阵列天线的GPS接收机的多径抑制方法

A Multipath Mitigation Method for Array Antenna-Based GPS Receiver

提出一种新的用于阵列天线GPS接收机的多径抑制方法。考虑到通常GPS视线信号的来波方向与多径的来波方向不同,在每个导航数据符号位内测距(C/A)码重复,通过对阵列接收的信号矢量与它本身的延迟信号矢量互相关,提高接收机前端信噪比,再利用最大特征值法和前后向空间平滑技术准确地估计期望卫星视线信号(LOSS)的来波方向。最后综合多个GSC子阵列有效地降低了相关多径对码跟踪精度的影响。仿真结果显示,该方法能使接收机在与LOSS码同步前准确估计LOSS的角度信息,有效抑制相关多径,且鉴相结果准确。

A novel multipath mitigation method for based array antenna GPS receiver is proposed. Considering that the direction of arrival （DOA） of line-of-sight-signal （LOSS） is different from the DOA of multipath, and the C/A-code is repeated within each navigation data bit symbol, the proposed method can improve signal to noise ratio （SNR）in the front end of receiver by constructing cross-correlation between the received signal vector and its own delay signal vector, and then both max eigenvalue method and forward-backward spatial smoothing technique are used to estimate the DOA of LOSS. Finally, multiple adaptive GSC subarrays are integrated to reduce the influence of correlated muhipaths on the code tracking accuracy. Simulation results show that the method can estimate the DOA of LOSS effectively before synchronizing with the LOSS code, mitigate the corretated multipaths effectively, and obtain accurate discriminator results.