MIMO探地雷达随机步进频信号旁瓣抑制

Sidelobe Suppression of Random Stepped Frequency Signal in MIMO Ground Penetrating Radar

针对MIMO探地雷达中随机步进频信号的距离旁瓣较高的问题,提出了一种基于快速二阶锥优化问题的旁瓣抑制方法。该方法首先通过建立随机步进频信号模型对回波信号进行预处理,然后基于回波信号的旁瓣特点将旁瓣抑制问题转化为以信号的峰值旁瓣构建目标函数,以主峰损失、峰值旁瓣和积分旁瓣联合约束的二阶锥优化问题,最后使用内点法求解二阶锥规划问题,以此得到最优的旁瓣滤波器系数。仿真和实测数据处理结果表明,设计的失配滤波器能够在较低主峰损耗的情况下,有效降低峰值旁瓣电平和积分旁瓣电平,提高信号的主旁瓣比。该方法为MIMO探地雷达中的距离旁瓣问题提供了有效解决思路,有望在工程应用中提高探地雷达的性能。

Aiming at the problem of high range sidelobe of random stepped frequency signal in MIMO ground penetrating radar,a sidelobe suppression method based on fast second⁃order cone optimization problem is proposed in this paper.The echo signal is firstly preprocessed by establishing a random stepped frequency signal model.Then,based on the sidelobe characteristics of the echo signal,the sidelobe suppression problem is transformed into a second⁃order cone optimization problem that the objective function is established by the peak sidelobe of the signal,and the joint constraints are resulted from the main peak loss,the peak sidelobe and the integral sidelobe.Finally,the interior point method is used to solve the optimization problem to obtain the optimal sidelope filter coefficients.The simulation and measured data processing results show that the designed mismatch filter can effectively reduce the peak sidelobe level and integral sidelobe level and improve the main sidelobe ratio of the signal under the condition of low main peak loss.This method provides an effective solution to the range sidelobe problem in MIMO ground penetrating radar,and is expected to improve the performance of ground penetrating radar in engineering applications.