调频斜率捷变联合BFT抑制密集假目标干扰算法

为实现相参雷达有效抑制密集假目标干扰，提出一种调频斜率捷变联合双正交傅里叶变换的干扰抑制算法。在自卫式干扰条件下，雷达发射调频斜率捷变线性调频信号波形并接收1个相干处理间隔回波进行处理。首先，通过匹配相关运算法估计受干扰段回波的平均时延，并根据时延截取受干扰段回波；然后，利用双正交傅里叶变换将回波信号转换至调频斜率域，利用调频斜率差异分离真实目标回波与干扰信号，并设计遮盖窗对干扰峰值位置进行遮盖；其次，通过双正交傅里叶逆变换恢复真实目标回波；最后进行脉冲压缩、相参积累进一步抑制干扰。通过仿真实验验证了方法的可行性以及在不同场景下的有效性。效能分析结果表明经干扰抑制后真实目标检测概率大幅提高，且算法在应对假目标数量较多场景时具备优势。

A Dense False Target Jamming Suppression Algorithm Based on Slope Varying LFM Combined with BFT

? ?In order to effectively suppress dense false target jamming by coherent radar， a jamming suppression algorithm based on slope varying combined with BFT（Biorthogonal Fourier Transform）is proposed. Under the condition of self-defense jamming， the radar transmits slope varying LFM（linear frequency modulation） waveform and receives 1 coherent processing interval echo and process it. Firstly， the average delay of echoes in the interfered segment is estimated by matching correlation operation， and the part of the echo that was disturbed are intercepted according to the delay. Secondly， the echo signal is converted to the slope domain by Biorthogonal Fourier Transform， and the difference of the slope is used to separate the real target echo from the interference signal， and a filter windows is designed in the frequency modulation slope domain to cover the position of the interference peaks； Then， the real target echo is recovered by IBFT（Inverse Biorthogonal Fourier Transform）； Finally， pulse compression and coherent accumulation are used to further suppress jamming. The feasibility of the method and its effectiveness in different scenarios are verified through simulation experiments. After interference suppression， the detection probability of real targets is greatly improved.The effectiveness analysis results show that the detection probability of real targets is greatly improved after interference suppression， and the algorithm has advantages in dealing with scenes with a large number of false targets.