干扰条件下的“北斗”信号解扩重构DOA估计

在干扰条件下,卫星导航抗干扰波束形成算法往往需要卫星信号波达方向(Direction-of-Arrival,DOA)的先验信息。但当存在低信噪比信号或主动干扰源时,常规的DOA估计算法性能急剧下降甚至失效。针对此问题,提出了一种被干扰信号压制的低信噪比“北斗”信号的DOA估计算法。该算法首先通过对接收信号进行子空间投影抑制干扰信号,然后对抑制干扰后的信号进行解扩重构处理,最后通过多重信号分类算法完成对“北斗”信号的DOA估计。仿真结果表明,在干扰信号干信比80dB条件下,“北斗”信号DOA估计误差在5°以内,为下一步进行波束形成计算提供了高精度的入射角信息。

Despread-reconstruction DOA estimation for Beidou signals with interferences

Under the interferences environment,a prior knowledge of the direction-of-arrival(DOA) estimation of Global Navigation Satellite System(GNSS) signals is significant for beam-forming algorithms.The performance of normal DOA estimation algorithms is poor or disabled in the presence of low signal-to- noise ratio(SNR) signals or active interference signals.To solve this problem,a DOA estimation algorithm is proposed for low SNR Beidou signals in the presence of interference signals.Firstly,the interference signals are suppressed by subspace orthogonal projection.Then,the Beidou signals are improved by despread-reconstruction processing,which are used to estimate the DOA of the Beidou signals by the multiple signal classification(MUSIC) algorithm.Simulation results show that,when jamming-to-signal ratio(JSR) is 80 dB ,the estimation error of DOA estimation is within 5° for Beidou signals,which provides high-precision angle of arrival information for beam-forming.