改进的三次相位函数法LFM雷达信号参数估计

The parameter estimation of an LFM radar signal based on a modified cubic phase function

为了研究对线性调频(LFM)雷达信号的参数估计,提出了利用改进的三次相位函数法对LFM雷达信号进行参数估计.三次相位函数法可提取信号的相位函数的各项系数,并且只需通过二阶非线性变换在信号参数空间形成最大值来进行估计参数,具有较高的精度和良好的低信噪比能力,但是计算量较大.针对三次相位函数法计算量大的问题,提出调频斜率搜索范围设定准则及双尺度调频斜率搜索法,可减少大量计算量,同时保持了低信噪比下的算法精度.仿真测试结果表明,新算法有效地减小了计算量,并且保证了低信噪比下的算法精度,算法性能得到了提高.

In order to explore the problem of parameter estimation for linear frequency modulation （LFM） radar signals, the parameter estimation of an LFM radar signal based on a modified cubic phase function was proposed. The method, known as the cubic phase function （ CPF）, can be used to achieve parameter estimation of LFM and NLFM signals; it can also extract the phase function coefficients. The CPF can conduct parameter estimation with the parameter space maximum value by second order nonlinear transformation, which has high precision and favorable low signal-to-noise ratio （SNR） ability. The computation of this algorithm is very large. For this problem, the search range criterion was proposed by using the pulse leading edge and pulse width information. In addition, a method called the dual-scale search of the frequency slope was brought forward to reduce the computation; this method also can maintain the accuracy of the algorithm in low SNR. Simulation results show that the computing time has been reduced and the precision has been ensured in low SNR; the performance of the algorithm has been improved.