现有全脉冲结构波形与处理方法,如相位编码波形匹配处理存在多普勒容忍度差的固有缺陷,线性调频(linear frequency modulation,LFM)波形加窗处理降低了距离分辨率和信噪比(signal-to-noise ratio,SNR)增益,难以适应高速多目标探测的任...现有全脉冲结构波形与处理方法,如相位编码波形匹配处理存在多普勒容忍度差的固有缺陷,线性调频(linear frequency modulation,LFM)波形加窗处理降低了距离分辨率和信噪比(signal-to-noise ratio,SNR)增益,难以适应高速多目标探测的任务需求。为此,本文提出了一种面向高速目标探测的多子脉冲结构波形设计与处理方法。首先,构建具有多子脉冲结构波形的回波模型,利用分段子脉冲压缩处理和子脉冲间相参处理方法,导出多子脉冲结构波形的距离-多普勒响应函数;然后,根据感兴趣的目标距离速度区间,建立恒模约束下以最小化加权积分距离-多普勒旁瓣电平为目标函数的多子脉冲结构波形优化设计问题;最后,引入坐标下降(coordinate descent,CD)优化框架,将高维非凸约束优化问题的求解转变为多个一维优化问题的迭代求解,且推导出这些低维问题的闭式解。仿真表明,所设计的多子脉冲结构波形具有较好的多普勒容忍度和较低的局部距离-多普勒旁瓣电平,且在高速多目标认知探测场景下,相比于LFM波形、模糊函数优化波形和LFM-noise波形具有更好的高速目标探测能力。展开更多
Most of the existing non-line-of-sight(NLOS)localization methods depend on the layout information of the scene which is difficult to be obtained in advance in the practical application scenarios.To solve the problem,a...Most of the existing non-line-of-sight(NLOS)localization methods depend on the layout information of the scene which is difficult to be obtained in advance in the practical application scenarios.To solve the problem,an NLOS target localization method in unknown L-shaped corridor based ultra-wideband(UWB)multiple-input multiple-output(MIMO)radar is proposed in this paper.Firstly,the multipath propagation model of Lshaped corridor is established.Then,the localization process is analyzed by the propagation characteristics of diffraction and reflection.Specifically,two different back-projection imaging processes are performed on the radar echo,and the positions of focus regions in the two images are extracted to generate candidate targets.Furthermore,the distances of propagation paths corresponding to each candidate target are calculated,and then the similarity between each candidate target and the target is evaluated by employing two matching factors.The locations of the targets and the width of the corridor are determined based on the matching rules.Finally,two experiments are carried out to demonstrate that the method can effectively obtain the target positions and unknown scene information even when partial paths are lost.展开更多
To enhance direction of arrival(DOA)estimation accuracy,this paper proposes a low-cost method for calibrating farfield steering vectors of large aperture millimeter wave radar(mmWR).To this end,we first derive the ste...To enhance direction of arrival(DOA)estimation accuracy,this paper proposes a low-cost method for calibrating farfield steering vectors of large aperture millimeter wave radar(mmWR).To this end,we first derive the steering vectors with amplitude and phase errors,assuming that mmWR works in the time-sharing mode.Then,approximate relationship between the near-field calibration steering vector and the far-field calibration steering vector is analyzed,which is used to accomplish the mapping between the two of them.Finally,simulation results verify that the proposed method can effectively improve the angle measurement accuracy of mmWR with existing amplitude and phase errors.展开更多
针对分布式多输入多输出(Multiple-input Multiple-output,MIMO)雷达回波信号相参积累问题,提出了一种利用信息熵作为优化准则的多节点回波相位补偿与相参积累方法。采用正交频分复用线性调频信号(Orthogonal Frequency Division Multip...针对分布式多输入多输出(Multiple-input Multiple-output,MIMO)雷达回波信号相参积累问题,提出了一种利用信息熵作为优化准则的多节点回波相位补偿与相参积累方法。采用正交频分复用线性调频信号(Orthogonal Frequency Division Multiplexing Linear Frequency Modulated Signal,OFDM-LFM)作为发射波形,通过匹配滤波完成耦合回波分离和脉冲压缩,然后在频域进行频移操作消除步进频的相位影响,利用信息熵估计距离对齐后的多节点回波相位差,随后构建相应的相位补偿函数,进而完成各节点回波的相位差异补偿,最终得到分布式MIMO雷达多节点回波信号的相参积累结果。所提方法可同时处理多个节点回波,仿真实验验证了该方法的有效性。展开更多
文摘现有全脉冲结构波形与处理方法,如相位编码波形匹配处理存在多普勒容忍度差的固有缺陷,线性调频(linear frequency modulation,LFM)波形加窗处理降低了距离分辨率和信噪比(signal-to-noise ratio,SNR)增益,难以适应高速多目标探测的任务需求。为此,本文提出了一种面向高速目标探测的多子脉冲结构波形设计与处理方法。首先,构建具有多子脉冲结构波形的回波模型,利用分段子脉冲压缩处理和子脉冲间相参处理方法,导出多子脉冲结构波形的距离-多普勒响应函数;然后,根据感兴趣的目标距离速度区间,建立恒模约束下以最小化加权积分距离-多普勒旁瓣电平为目标函数的多子脉冲结构波形优化设计问题;最后,引入坐标下降(coordinate descent,CD)优化框架,将高维非凸约束优化问题的求解转变为多个一维优化问题的迭代求解,且推导出这些低维问题的闭式解。仿真表明,所设计的多子脉冲结构波形具有较好的多普勒容忍度和较低的局部距离-多普勒旁瓣电平,且在高速多目标认知探测场景下,相比于LFM波形、模糊函数优化波形和LFM-noise波形具有更好的高速目标探测能力。
基金supported by National Natural Science Foundation of China(U20B2070,62001091)Sichuan Science and Technology Program(2022YFS0531).
文摘Most of the existing non-line-of-sight(NLOS)localization methods depend on the layout information of the scene which is difficult to be obtained in advance in the practical application scenarios.To solve the problem,an NLOS target localization method in unknown L-shaped corridor based ultra-wideband(UWB)multiple-input multiple-output(MIMO)radar is proposed in this paper.Firstly,the multipath propagation model of Lshaped corridor is established.Then,the localization process is analyzed by the propagation characteristics of diffraction and reflection.Specifically,two different back-projection imaging processes are performed on the radar echo,and the positions of focus regions in the two images are extracted to generate candidate targets.Furthermore,the distances of propagation paths corresponding to each candidate target are calculated,and then the similarity between each candidate target and the target is evaluated by employing two matching factors.The locations of the targets and the width of the corridor are determined based on the matching rules.Finally,two experiments are carried out to demonstrate that the method can effectively obtain the target positions and unknown scene information even when partial paths are lost.
文摘To enhance direction of arrival(DOA)estimation accuracy,this paper proposes a low-cost method for calibrating farfield steering vectors of large aperture millimeter wave radar(mmWR).To this end,we first derive the steering vectors with amplitude and phase errors,assuming that mmWR works in the time-sharing mode.Then,approximate relationship between the near-field calibration steering vector and the far-field calibration steering vector is analyzed,which is used to accomplish the mapping between the two of them.Finally,simulation results verify that the proposed method can effectively improve the angle measurement accuracy of mmWR with existing amplitude and phase errors.
文摘针对分布式多输入多输出(Multiple-input Multiple-output,MIMO)雷达回波信号相参积累问题,提出了一种利用信息熵作为优化准则的多节点回波相位补偿与相参积累方法。采用正交频分复用线性调频信号(Orthogonal Frequency Division Multiplexing Linear Frequency Modulated Signal,OFDM-LFM)作为发射波形,通过匹配滤波完成耦合回波分离和脉冲压缩,然后在频域进行频移操作消除步进频的相位影响,利用信息熵估计距离对齐后的多节点回波相位差,随后构建相应的相位补偿函数,进而完成各节点回波的相位差异补偿,最终得到分布式MIMO雷达多节点回波信号的相参积累结果。所提方法可同时处理多个节点回波,仿真实验验证了该方法的有效性。
