GNSS接收机抗干扰自适应调零技术性能估计

GNSS抗干扰技术中常采用功率倒置算法(PI)来得到自适应波束形成的零陷。信干比为80dB时,PI算法能准确识别干扰的方向,抗干扰分辨率好,但当信干比降低到20dB左右时,在射频干扰信号方向谱周围会形成大量带状的零陷,干扰信号的分辨率恶化严重。空间谱估计中的多重信号分类(MUSIC)算法具备超分辨率特性,通过信号子空间和噪声子空间的正交功率最小化原理,采用空间二维谱峰搜索方位角和仰角,能够准确进行DOA估计,有效区分有用信号和干扰信号。在高信干比条件下,基于MUSIC算法的最小功率估计抑制深度明显好于传统的PI算法;在低信干比条件下,MUSIC-PI算法在干扰信号方向谱判别及零陷抑制方面依然有效,而传统的PI算法失效。计算机仿真结果验证了该方法在GNSS抗干扰领域的有效性和鲁棒性。

Performance Estimates of GNSS Receiver Jamming with Adaptive

A Power Inversion adaptive algorithm(PI)is often used to get the nulling beamform inGNSS jamming techniques.When the signal to interference ratio is 80dB,a PI algorithm can accu-rately identify the direction of jamming at high resolution.However,a large ribbon nulling will formaround the direction of the RF interference signal in the algorithm.If the signal to interference ratioreduces to 20dB,the resolution of the interference signal will seriously deteriorate.The multiple sig-nal classification(MUSIC)algorithm has super-resolution features;it can achieve power minimizationthrough the signal subspace and noise subspace orthogonal principles.A two-dimensional spectralpeak search technology is used in searching the azimuth and elevation of interference to accurately esti-mate the DOA and effectively distinguish the desired signal and the interference signal.When the sig-nal to interference ratio is high,the suppression depth from the MUSIC-PI algorithm is significantlybetter than the traditional power inversion algorithm.In a low signal-to-interference ratio condition,the MUSIC-PI algorithm is still valid when suppressing the interference in the right direction,but thepower inversion algorithm cannot discriminate the direction of interference accurately.Computer sim-ulation results show the effective and robust performance of the MUSIC algorithm in the GNSS jam-ming field.