卫星导航终端是通过对接收信号频谱进行干扰检测、判别置零,实现窄带干扰抑制。然而,在接收信号时域离散化过程中会对离散信号序列产生截断,这在时域上表现为离散信号加上一个矩形窗。该时域截断会导致信号频谱泄露,造成信号频谱检测和判别置零的有效性下降,降低终端抗窄带干扰能力。文中通过研究并选择合适的离散信号加窗函数,抑制信号旁瓣减少频谱泄露,提升系统抗窄带干扰能力。研究表明:不论是在大干信比(100 dB)条件还是小干信比(40 dB)条件下,凯撒窗性能都优于传统的矩形窗。

In the research of anti-narrow band interference in satellite navigation system, narrow-band interference suppression is achieved by detecting and discriminating the interference of the received signal spectrum. However, in the time domain discretization of the received signal, the discrete signal sequence will be truncated, which appears as a discrete signal with a rectangular window in the time domain. This time-domain truncation can lead to signal frequency domain leakage, and resulting in signal spectrum detection and determine the zero-setting failure, reduce ability of the system to against the narrow-band interference. In this paper, we select the appropriate windowing function of discrete signal to suppress the sidelobe of signal and reduce the leakage of spectrum to enhance the ability of the system to resist narrowband interference. The results show that when the ratio of dry letter is less than 40 dB, the comprehensive performance of rectangular window function is the best. When the interference ratio is more than 70 dB, the performance of Caesar window is the best.

TN957.51

国家自然科学基金资助项目(61471117)