改进的乘积型核函数二次调频信号的参数估计

该文提出一种基于改进乘积型核函数的二次调频信号的参数估计方法。首先，对信号乘以自身的共轭反转并做相位匹配变换，通过积累后信号最大值位置得到信号的调频率估计值；然后，再补偿掉原信号的调频率，对解调频(dechirp)后的信号构造新的乘积型核函数，并变换到2维时间-时延域，沿时间和时延轴分别做相位匹配变换和傅里叶变换，在变换后的调频率变化率-频率平面通过最大值的位置即可同时得到调频率变化率和中心频率的估计值，对补偿掉相位的信号取均值并求模得到幅度值，从而实现二次调频信号的参数估计和重构。可见，该方法避免了对所有相位参数的迭代搜索，提高了运算效率。最后，对单分量和多分量二次调频信号的仿真结果证明了该方法的有效性。

Parameter Estimation of Quadratic Frequency Modulated Signal Based on Improved Product Kernel Function

A new method for estimating parameters of quadratic frequency modulated signals is proposed basing on a product kernel function. Firstly, the signal is multiplied by its conjugate reverse signal with the phase-matching transformation being performed, and then the estimated value of the chirp rate can be obtained by searching one-dimension maximum position of accumulated signals. Secondly, the chirp rate of the signal is compensated and a new product kernel function for the dechirped signal is structured to transform it into the two-dimensional time-lag domain, and the phase-matching transformation and FFT respectively are performed along time and lag axis. As a result, by the maximum searching in the new change rate of the chirp rate-frequency domain after transformation, the estimated values of both the change rate of the chirp rate and the center frequency can be obtained, with the phase of the signal being able to compensated and the amplitude estimated by calculating the magnitude of its average, thereby leading to the reconstruction of the signal. It is shown that the proposed method precludes the iterative search of all phase parameters and improves the operational efficiency. Finally, the paper presents the simulated results that confirm the effectiveness of this method.