具有空时二维分辨能力的多径干扰抑制算法

摘要

针对全球卫星导航系统(Global Navigation Satellite System,GNSS)中的多径干扰抑制问题,本文提出了一种有效的算法,该算法首先对接收到的数据进行捕获,以获得各卫星信号的参数粗估结果,接着利用WRELAX(Weighted RELAXation)技术,在空时二维空间中逐一估计出直达卫星信号和多径干扰的来向、码时延和幅度信息;并根据所估计到的参数来区分多径干扰和直达信号;此外,本文在进行二维参数估计时,根据捕获到的码时延的信息,限定码时延的搜索范围的方法显著降低了算法运算量.由于空时二维处理能够同时从空域和时域区分直达卫星信号和多径干扰,因此能够更好地实现多径干扰抑制.最后,通过仿真实验验证了本文算法较之传统多径干扰抑制算法的优越性.%This paper studied the multipath mitigation in Global Navigation Satellite System (GNSS).A novel efficient algorithm with moderate computation burden is proposed,which firstly acquire the received data to obtain a rough estimation the satellite signal parameters.Then the Weighted RELAXation (WRELAX) technology,which was proposed to estimate the spatial parameter initially,is generalized to the space-time domain,termed as ST-RELAX.By using the ST-RELAX algorithm,the space-time parameters,e.g.direction of arrival (DOA),time delay and amplitude of both the line of sight (LOS) signal and the multipath are estimated.In addition,based on the code delay obtained from the acquisition process,the code delay searching interval in the 2-D parameter estimation process can be limited to reduce the computation burden.Hence,both the spatial and the time domain information can be used,the multipath can be mitigated more efficiently.Finally,the simulation results show that the proposed algorithm is superior to the traditional multipath mitigation algorithms.