基于子空间跟踪的宽带短波探测低失真窄带干扰抑制算法

短波信道中窄带干扰分布密集，导致宽带短波探测系统接收信噪比恶化。针对传统子空间跟踪干扰抑制后信号失真较大而严重影响电离层信道参数精确提取的问题，论文基于自适应子空间跟踪提出了一种新颖的双子空间频谱标识算法，在抑制干扰的同时有效减小了信号失真。该算法利用基带探测信号频谱对称特性，通过干扰子空间标识得到非对称干扰频带内的有用信号；且使用信号子空间标识将干扰频带与信号频带有效分离实现干扰抑制。仿真分析与实测数据处理效果表明，双子空间频谱标识算法较大程度地保持了接收信号的原始状态，处理后数据较传统算法可以获得更高的相关后信噪比，大增加了探测信号的捕获概率，对于短波电离层信道探测具有特殊的重要意义。 

A Low Distortion Algorithm Based on Subspace Tracking for Narrow-band Interference Rejection in Wideband Shortwave Probe

Spectrum of shortwave channels becomes less and less,narrow-band interference(NBI) has such high density that signal-to-noise ratio(SNR) of received signal worsens badly in the wideband shortwave probe system.Traditional interference rejection algorithms based on subspace tracking bring high distortion of the probe signal,which results in disadvantageous influence to the high accuracy estimation of channel parameters.This paper presents a novel interference suppression algorithm based on adaptive subspace tracking which not only realizes interference rejection but also effectively reduces distortion of the probe signal.Spectrum of the base-band probe signal is symmetrical,so this algorithm can get the probe signal in the band of interference using mark of interference-subspace spectrum;and separates the band of NBI from the signal effectively via mark of signal-subspace spectrum.The simulation and data processing of our probe system both demonstrate that the new algorithm can keep the original status of the received signal and obtain higher SNR of correlation compared to traditional algorithm,which can consumedly increase the acquisition probability of received signal.So our new algorithm called mark of two-subspace spectrum has important meaning to the high accuracy estimation of the shortwave ionosphere parameter.