基于频谱细化的线性调频信号参数估计

针对现有的线性调频(linear frequency modulation,LFM)信号参数估计算法运算量大、实时性差的问题,提出了基于频谱细化的参数快速估计算法。首先对中频采样信号与其延迟逐点相乘,并对产生的新序列做FFT运算,初步粗略估计出LFM信号的调频斜率,然后运用频谱细化方法,即chirp-Z变换,估计出精确的调频斜率。在此基础上,对原信号直接解线调,分析解线调后的信号频谱,估计出信号的起始频率,同样采用频谱细化方法提高估计精度。仿真结果表明算法的有效性。

LFM signal parameter estimation based on spectrum zoom

The existing LFM signal parameter estimation algorithm is hard to fulfill tasks in a real-time system for heavy computation loads.A fast efficient algorithm based on spectrum zoom analysis is proposed.First,the spectrum of the array multiplication of the IF sample and its delayed version is analyzed to obtain the rough estimate of the chirp rate,then chirp-Z transform is applied to estimate the chirp rate accurately.Second,using the direct de-chirp method with the estimated chirp rate,the estimation of the initial frequency of the LFM signal can be done.The spectrum zoom method can also be used to improve its accuracy.Simulation results show the proposed algorithm is effective.