基于1-bit的北斗卫星外辐射源目标定位方法研究

    Research on the method of Beidou satellite signals based on 1-bit sampling as external radiation sources for target localization

    • 摘要: 对于北斗卫星外辐射源目标定位,为了获得较高的定位精度,需要进行处理的数据较多,而1-bit采样相比于高精度采样具有成本低、运算量小、数据量小等优势,因此将1-bit采样应用于卫星信号处理,并设计了一种外辐射源目标定位方案。首先,介绍1-bit采样原理以及性能损失与边界条件,发现在低信噪比的情况下,其性能损失相对较小;其次,设计基于1-bit采样的北斗卫星信号作为外辐射源定位目标的方案,通过直达波信号重构、匹配滤波和相干积累的处理方法提高目标散射回波信号的信噪比,并利用数字波束形成技术将目标散射回波与直达波从方位上进行区分,降低直达波对目标散射回波的影响;最后,对信号处理过程进行建模仿真,实验结果表明,虽然相比于高精度采样具有性能损失,但该方案可以实现对1-bit采样目标散射回波信号的检测,并对目标位置和速度进行有效估计。

       

      Abstract: For Beidou satellite external radiation source target positioning, in order to achieve higher positioning accuracy, a considerable amount of data processing is required. 1-bit sampling, compared to high-precision sampling, offers advantages such as lower cost, reduced computational load, and smaller data volume. Therefore, 1-bit sampling is applied to satellite signal processing, and a target positioning scheme using external radiation sources is designed. First, the principle of 1-bit sampling, as well as its performance loss and boundary conditions, are introduced, and it is found that the performance loss is relatively small under low SNR conditions. Then, a scheme is designed for using Beidou satellite signals based on 1-bit sampling as an external radiation source for target localization. The scheme employs direct wave signal reconstruction, matched filtering, and coherent accumulation processing methods to enhance the SNR of the target- scattered echo signals. Digital beamforming technology is utilized to distinguish the target- scattered echoes from the direct waves in terms of azimuth, thereby reducing the impact of the direct waves on the target-scattered echoes. Modeling and simulation of the signal processing procedure are conducted, and the experimental results indicate that although there is a performance loss compared to high-precision sampling, the proposed scheme can detect the target-scattered echo signals after 1-bit sampling and effectively estimate the target’s position and velocity.