摘要
针对全球导航卫星系统中的多径干扰抑制问题,提出了一种有效的低复杂度多径干扰抑制算法,在直达信号和多径干扰来向角(DOA)未知的情况下,利用RELAX算法,通过反复迭代的思想逐一估计出直达信号和多径干扰的DOA和幅度,进而识别多径干扰,利用线性约束最小方差无畸变波束形成技术,在直达信号方向形成增益与在多径干扰方向形成零陷而抑制多径干扰,并进行了仿真试验。分析结果表明:当多径干扰部分相干时,RELAX算法估计的DOA均方根误差比MUSIC算法低了约12dB;当多径干扰完全相干时,RELAX算法估计的DOA均方根误差比MUSIC算法低了约25dB;所提算法能够准确估计出直达信号和多径干扰的DOA,保证通过波束形成零陷空域多径干扰,使得进入跟踪环路的信号非常洁净,处理后的码相位跟踪误差接近于0。
Aiming at the multipath interference suppression problem in global navigation satellite system（GNSS）, an efficient multipath interference suppression algorithm with low complexity was proposed. Under the unknown directions of arrival （DOAs） of direct signal and multipath interference, the RELAX algorithm was used to estimate the DOAs and amplitudes of direct signal and multipath interference one by one through repeated iteration idea, and then to distinguish multipath interference. The beam forming technology without distortion based on linearly constrained minimum variance（LCMV） was used to form gain at direct signal direction and null at multipath interference direction, and then to suppress multipath interference. The simulation test was carried out. Analysis result shows that when multipath interferences are partially coherent, the root mean square error of DOA estimated by RELAX algorithm is about 12 dB lower than the value estimated by MUSIC algorithm. When multipath interferences are completely coherent, the root mean square error of DOA estimated by RELAX algorithm is about 25 dB lower than the value estimated by MUSIC algorithm. The proposed algorithm can accurately estimate the DOAs of direct signal and multipath interference, which can ensure nulling the multipath interference in airspace through beam forming to make the signal entering the tracking loop very clean. The processed tracking error of code phase is close to 0. 6 figs, 24 refs.
作者
贾琼琼
吴仁彪
王文益
卢丹
王璐
JIA Qiong-qiong WU Ren-biao WANG Wen-yi LU Dan WANG Lu(Tianjin Key Laboratory of Intelligent Signal and Image Processing, Civil Aviation University of China, Tianjin 300300, Chin)
出处
《交通运输工程学报》
EI
CSCD
北大核心
2017年第2期151-158,共8页
Journal of Traffic and Transportation Engineering
基金
国家自然科学基金项目(61471363)
