基于FRFT的多分量LFM信号检测与参数估计方法

针对传统方法搜寻效率低的问题，采取瞄准搜寻策略，提出一种快速精确地检测和估计多分量线性调频（LFM）信号参数的方法。推导出LFM信号的分数阶长度和旋转角度间的近似关系；利用分数阶幅度随旋转角度变化规律，提出一种高效搜寻最优旋转角度的算法，分析得出该算法的计算量较小，相比于传统算法具有较大优势。在低信噪比情况下，进行两次S-G滤波可显著提高检测概率。仿真结果表明，所提方法在低信噪比和存在分量间信号干扰的情况下，能可靠检测和精确估计多分量LFM信号参数。 

Multicomponent LFM signal detection and parameter estimation method based on FRFT

Aimed at the low searching efficiency of traditional methods, this paper, using aimed searching strategy, proposes a fast and accurate algorithm for detecting and estimating multicomponent Linear Frequency Modulation (LFM) signal parameters.The approximate relation between the power spectrum width and rotation angle of LFM signal in fractional domain is deduced.This paper presents an efficient algorithm for searching the optimal rotation angle using the variation law of power spectrum amplitude with rotation angle in fractional domain.And it is concluded that the computation of this algorithm is small and has great advantages compared with the traditional algorithm.In the case of low SNR, two times of S-G filtering can significantly improve the detection probability. Simulation results show that the algorithm can reliably detect and accurately estimate multicomponent LFM signal parameters under the condition of low SNR and interference between components.