基于STFRFT的脉冲干扰抑制方法研究

为了解决航空无线电导航服务频段附近的脉冲干扰影响接收机工作的问题,并进一步提高GNSS系统的抗干扰能力,提出了基于STFRFT(short time fractional Fourier transform)的脉冲干扰抑制方法。首先确定接收信号的最佳旋转阶次,再对信号进行STFRFT,通过坐标旋转得到时频面的二维分布,在最佳阶次下采用自适应时变滤波器实现对干扰和信号的分离,进而抑制干扰。仿真结果表明,和几种传统方法相比,基于STFRFT的自适应滤波算法剔除干扰效果最好,在抑制脉冲干扰的同时保留了更多有用信号。结合STFRFT技术和自适应时变滤波技术提高了抑制脉冲干扰的能力,可为航空无线电导航服务的脉冲抗干扰技术提供参考依据。

Research on impulse interference suppression method based on short time fractional Fourier transform

In order to solve the problem that the impulse interference near the service frequency band of aviation radio navigation affects the receiver, and further improve the anti-jamming ability of GNSS system, a impulse interference suppression method based on STFRFT (short time fractional Fourier transform) was proposed. The optimal rotation order of the received signal was determined, and STFRFT was applied to the signal to obtain the two-dimensional distribution of time-frequency surface through coordinate rotation. Under the optimal order, the adaptive time-varying filter was used to separate the interference and the signal, so as to suppress the interference. The simulation results show that the adaptive filtering algorithm based on STFRFT has the best effect of eliminating interference compared with several traditional methods, and retains more useful signals while suppressing impulse interference. By combining STFRFT and adaptive time-varying filtering technology, the ability of suppressing impulse interference is improved, which provides some reference for the impulse anti-jamming technology of aviation radio navigation service.