GPS接收机抑制LFM干扰空时子空间投影方法

根据GPS接收机接收信号、噪声和线性调频(LFM)干扰在时频平面上的不同分布特点,用STFT-Hough变换进行干扰的检测和参数估计;将子空间投影方法与空时信号处理相结合,构造出空时二维干扰子空间,利用子空间投影方法进行干扰抑制.文中给出干扰参数估计和空时子空间投影抗干扰的具体步骤,推导出系统输出信干噪比的解析表达式,分析了干扰参数估计误差的影响.同其它抗LFM干扰方法相比,本文方法对干扰参数估计更准确、计算量更小;空时子空间投影方法引入更多自由度,抗干扰性能进一步提高;结构简单,具有较高的可行性和实用性.仿真试验验证了该方法能有效抑制LFM干扰.

LFM interference suppression in GPS receiver using space-time subspace projection techniques

A new approach is proposed for LFM interference suppression in GPS receiver.It combines subspace projection with space-time processing based on the characters of GPS signal,noise and LFM interferences.Space-time interference subspace is construc- ted through interference detection and parameters estimation using STFT-Hough transformation.Then the interferences suppression is con- ducted using subspace projection techniques.The processing flow is provided;the output SINR expression is educed;and the infection of parameters estimation error is analyzed.Comparing with other techniques,it has an exacted and efficient estimation to interference parame- ters and a simple structure to suppress interferences.Space-time subspace projection technique provided more freedom for improving the an- ti-januner performance.The result of numerical simulation demonstrates that it is effective and efficient to LFM interference suppression.