基于子载波提取的OFDM无源雷达频率分集方法

为了解决当前正交频分复用(OFDM)无源雷达波束形成无法对分布于同一角度不同距离处的目标信号进行区别处理的问题，提出了一种基于回波信号子载波提取的频率分集新方法。通过对接收阵列不同通道OFDM数据提取不同频率的子载波信号并独立地进行处理，使得接收端波束图具有距离-角度依赖性，从而可实现对同一角度内不同距离处的目标分别处理，同时分析了不同频率分集处理参数对波束图性能的影响。该频率分集处理方式可以提高距离维信号处理自由度，使得接收波束能量可聚焦于期望目标点处从而提升雷达目标检测、定位和杂波抑制等性能。仿真分析表明OFDM无源雷达回波信号经频率分集处理后可获得点状波束图，并通过实测数据分析验证了该方法的有效性与实用性。

Frequency diverse method for OFDM passive radar based on subcarrier extraction

The beamforming method of current Orthogonal Frequency Division Multiplexing(OFDM) passive radar cannot effectively distinguish the target signals distributed at the same angle and different distances. A new frequency diverse processing method based on subcarrier extraction of passive radar receiving signal is proposed. The beampattern can be turned into range-angle dependent by extracting and processing different subcarriers independently for each receiving channel, thus the targets distributed at the same angle and different distances can be processed differently. And the effect of parameters in frequency diverse processing is also investigated. The increased degree of freedom in range dimension with frequency diverse processing can help focus the beam energy on the desired point in space, which improves the performance of radar in target detection, location, and clutter suppression. Simulation analysis shows that a dot-shaped beampattern can be obtained with frequency diverse processing for OFDM passive radar receiving signals, and the experimental results also verify the effectiveness and the practicability of the proposed method.