Wang Haitao, Lyu Xiaoyong, Liao Kefei
School of Information and Communication, Guilin University of Electronic Technology, Guilin 541004, China.
School of Information Engineering, Zhengzhou University, Zhengzhou 450001, China.
Sensors (Basel). 2021 Dec 24;22(1):117. doi: 10.3390/s22010117.
Passive radars based on long-term evolution (LTE) signals suffer from sever interferences. The interferences are not only from the base station used as the illuminator of opportunity (BS-IoO), but also from the other co-channel base stations (CCBS) working at the same frequency with the BS-IoO. Because the reference signals of the co-channel interferences are difficult to obtain, cancellation performance degrades seriously when traditional interference suppression methods are applied in LTE-based passive radar. This paper proposes a cascaded cancellation method based on the spatial spectrum cognition of interference. It consists of several cancellation loops. In each loop, the spatial spectrum of strong interferences is first recognized by using the cyclostationary characteristic of LTE signal and the compressed sensing technique. A clean reference signal of each interference is then reconstructed according to the spatial spectrum previously obtained. With the reference signal, the interferences are cancelled. At the end of each loop, the energy of the interference residual is estimated. If the interference residual is still strong, then the cancellation loop continues; otherwise it terminates. The proposed method can get good cancellation performance with a small-sized antenna array. Theoretical and simulation results demonstrate the effectiveness of the proposed method.
基于长期演进（LTE）信号的无源雷达受到严重干扰。这些干扰不仅来自用作机会照明器的基站（BS - IoO），还来自与BS - IoO工作在相同频率的其他同信道基站（CCBS）。由于同信道干扰的参考信号难以获取，当传统干扰抑制方法应用于基于LTE的无源雷达时，抵消性能会严重下降。本文提出了一种基于干扰空间谱认知的级联抵消方法。它由几个抵消环路组成。在每个环路中，首先利用LTE信号的循环平稳特性和压缩感知技术识别强干扰的空间谱。然后根据先前获得的空间谱重建每个干扰的纯净参考信号。利用该参考信号抵消干扰。在每个环路结束时，估计干扰残余的能量。如果干扰残余仍然很强，则抵消环路继续；否则终止。所提出的方法使用小型天线阵列就能获得良好的抵消性能。理论和仿真结果证明了该方法的有效性。
