基于时频分析的GNSS连续波干扰检测

Study of GNSS anti-interference performance based on time-frequency analysis

GNSS(Global Navigation Satellite System)信号在传播的过程中会受到各种连续波的干扰,以至于接收机很难根据GNSS信号进行准确的导航和定位。GNSS接收机接收到的信号是近平稳或者非平稳的,其统计量是时变函数。因此只了解信号在时域或频域的全局特性是远远不够的,还需要知道信号频谱随时间变化的情况。为了分析和处理非平稳信号,文章引入了时频分析的方法,利用其可以同时描述信号在时间和频率的能量密度和强度;通过短时傅里叶变换和Wigner-Ville分布分别处理被连续波干扰的GNSS信号,它们都能够捕获GNSS信号中连续波干扰的频率,再通过滤波器滤除连续波的干扰;利用Wigner-Ville分布和短时傅里叶变换,通过Matlab仿真分别检测GNSS信号中连续波干扰的频率,并比较两者性能的差异。

Global navigation satellite system （GNSS） signals will be affected by a variety of continuous wave interference in the process of transmission ,so that it is difficult to offer accurate navigation and position based on GNSS receiver signal .As the GNSS receiver’s signal is stationary or non-stationary , its statistic is a time-varying function ,so understanding global characteristics of the signal in time or frequency domain is not enough ,and it is necessary to know the signal spectrum changes over time .In order to analyze and deal with the non-stationary signals ,the time-frequency analysis method is intro-duced in this paper ,w hich can be used to describe the energy density and intensity of the signal in dif-ferent time and frequency .The short-time Fourier transform （STFT ） and Wigner-Ville distribution are used to process the continuous wave interference of GNSS signal respectively ,the continuous wave jamming signal spectrum in GNSS signal can be captured ,and the continuous wave interference is re-moved through the filter .Based on Matlab simulation ,the continuous wave jamming signal spectrum in GNSS signal distribution is detected with STFT and Wigner-Ville distribution respectively ,and their performance is compared .