Abstract:  Combined with the time-frequency characteristics of the Symmetrical Triangular Linear Frequency-Modulated Continuous Wave（STLFMCW）signal, this paper proposes a detection and parameter estimation method of STLFMCW using the periodic Fractional Fourier Transform（FRFT）. First of all, the energy accumulation characteristics of STLFMCW signal in periodic FRFT domain are analyzed, and the processing gain expression of the periodic FRFT for STLFMCW signal is derived. Furthermore, the probability statistical property of the noise in periodic FRFT domain is derived, and the detection threshold is determined adaptively. Due to the periodic accumulation characteristics of this method, the frequency-modulated period, starting time offset, chirp rate and carrier frequency are estimated well in low [SNR] by this method. Finally, the validity of the proposed method is validated.

Key words: symmetrical triangular linear frequency-modulated continuous wave, parameter estimation, periodic fractional Fourier transform, Radon-Ambiguity transform

摘要： 结合对称三角线性调频连续波（STLFMCW）信号的时频特性，提出了一种采用周期分数阶傅里叶变换（FRFT）的STLFMCW信号检测与参数估计方法。分析了STLFMCW信号在周期FRFT域的能量积累特性，推导了信号周期FRFT的处理增益表达式。利用噪声在周期FRFT域的概率统计特性实现了检测门限的自适应确定。由于具有周期积累特性，在低信噪比下，该方法对调频周期、起始时间偏移、调频斜率和载频具有较好的估计性能。最后，仿真验证了该方法的有效性。

关键词: 对称三角线性调频连续波, 参数估计, 周期分数阶傅里叶变换, Radon-Ambiguity变换