基于频谱对称性的GNSS频率抗干扰算法

GNSS frequency anti-jamming algorithm based on spectral symmetry

摘要:

传统的卫星导航信号频域抗干扰技术在接收信号的频域将干扰信号的谱线进行抑制从而达到抗干扰的目的，但在抑制干扰的同时抑制了部分信号，造成信号能量的损失。提出一种利用卫星导航信号频谱对称性的频域抗干扰算法，该方法利用卫星导航信号在频谱上的冗余性，在进行干扰谱线抑制的过程中利用与之对称未被干扰的谱线进行恢复，即可得到完整的信号频谱。分析北斗B3频点民码仿真数据表明：当干扰信号的频谱出现在中心频点的一侧时，该方法对干扰信号的带宽不敏感，即使干扰信号的频谱占到了信号频谱的一半，其输出信号的能量仍能保持稳定；与传统的方法相比，在进行干扰谱线抑制的过程中减小了信号能量的损失。仿真实验表明，在典型场景下，提出的方法与传统的置零法相比，载噪比提升约1 dB。

Abstract:

The traditional frequency-domain anti-interference technology of satellite navigation signals is processed in the frequency domain of the received signal, and the spectrum of the interference signal is suppressed to achieve anti-interference. This method suppresses the interference while suppressing part of the signal, resulting in the loss of signal energy. Aiming at this problem, a frequency domain anti-interference algorithm using the spectrum symmetry of satellite navigation signals is proposed. This method utilizes the spectrum redundancy of satellite navigation signals and uses it in the process of interference spectrum suppression. A complete signal spectrum can be obtained by recovering the symmetrical undisturbed lines. The simulation data of Beidou B3 frequency point code shows that when the spectrum of the interference signal appears on one side of the center frequency, the proposed method is not sensitive to the bandwidth of the interference signal, even if the spectrum of the interference signal accounts for half of the signal spectrum, the energy of the output signal remains stable; the loss of signal energy is reduced during the interference line rejection compared to that in conventional methods.Simulation experiments show that in typical scenarios, the proposed method can improve the carrier-to-noise ratio by about 1 dB compared with the traditional zero-setting method.