随机变频信号体制不仅可以降低系统瞬时带宽和数据采样率,还具有很强的抗干扰能力,然而,信号频率的随机变化导致现有目标散射中心估计方法失效。推导了随机变频信号的回波模型,在分析回波稀疏特性的基础上,提出了一种基于压缩感知的散射中心模型参数估计方法,将参数估计问题转化为压缩感知理论中的稀疏信号重构问题,并分析了感知矩阵对稀疏信号的重构性能。实验结果表明,所提方法能够在降低数据采样率的情况下对目标散射中心参数进行有效估计。
The random frequency signal format not only reduces the instantaneous band-width and data sampling rate, but also has the good characteristics of the radio-frequency immunity. However, the frequency of the signal changes randomly, which makes the traditional methods of scattering-center estimation invalid. Herein, the model of random frequency signal echoes was derived, and a novel parameter estimating method for scattering-center model was proposed based on the analysis of the radar echoes′ sparse characteristic. The parameters estimation was converted to the problem of sparse signal reconstruction in the framework of Compressed Sensing(CS). The performance of the sensing matrix was investigated. Experiment results show that the presented method is effect even for low sampling-rate condition.