In multi-LFM signal condition, Radon-Ambiguity Transform (RAT) of the strong LFM component has strong suppression effect on that of the weak LFM component. A method named as Recursive Filtering RAT (RFRAT) algorithm i...In multi-LFM signal condition, Radon-Ambiguity Transform (RAT) of the strong LFM component has strong suppression effect on that of the weak LFM component. A method named as Recursive Filtering RAT (RFRAT) algorithm is proposed for solving this problem. By fully using of the Maximum Likelihood (ML) estimation value of the frequency modulation rate got by RAT, RFRAT can detect the noisy multi-LFM signals out step by step. The merit of this new method is validated by an illustrative example in low Signal-to-Noise-Ratio (SNR) condition.展开更多
将不同长度线性调频(Linear Frequency Modulation, LFM)信号装入矢量信号源,其载波频率设置为中频,分别采样其输出的不同长度的LFM信号,对输出的LFM信号进行脉冲压缩Matlab仿真处理。实验表明,在采样频率及输出幅度相同的条件下,102.00...将不同长度线性调频(Linear Frequency Modulation, LFM)信号装入矢量信号源,其载波频率设置为中频,分别采样其输出的不同长度的LFM信号,对输出的LFM信号进行脉冲压缩Matlab仿真处理。实验表明,在采样频率及输出幅度相同的条件下,102.00μs脉冲内LFM信号仿真处理后的信噪比和旁瓣抑制比,相较3.00μs的指标提高了13.35 dB和4.61dB。进一步说明了由组合脉冲组成的LFM发射波形信号,其脉压体制雷达存在近距离回波比远距离回波差问题。提出了一种复杂海洋环境下多目标探测方法,对海用脉压体制雷达真实回波性能进行了改善和提升。展开更多
针对多分量线性调频信号存在重叠、漏检现象,导致波达方向的估计存在较大误差问题,提出多分量线性调频信号分数阶傅里叶域量纲归一化方法。首先给出了多分量LFM信号的阵列模型,讨论了阵列模型信号时频坐标系进行量纲归一化。通过对相干...针对多分量线性调频信号存在重叠、漏检现象,导致波达方向的估计存在较大误差问题,提出多分量线性调频信号分数阶傅里叶域量纲归一化方法。首先给出了多分量LFM信号的阵列模型,讨论了阵列模型信号时频坐标系进行量纲归一化。通过对相干环境下分数阶傅里叶域进行量纲归一化操作,提高多分量信号在分数阶傅里叶域的分辨能力,保证信源数目估计的准确性。仿真结果表明该方法正确的识别信源组数,提高多分量信号波达方向估计精确度,信噪比低于-4 d B的信号抗干扰能力明显增强。展开更多
基金Supported by the National 973 Program(No.973-1-12)
文摘In multi-LFM signal condition, Radon-Ambiguity Transform (RAT) of the strong LFM component has strong suppression effect on that of the weak LFM component. A method named as Recursive Filtering RAT (RFRAT) algorithm is proposed for solving this problem. By fully using of the Maximum Likelihood (ML) estimation value of the frequency modulation rate got by RAT, RFRAT can detect the noisy multi-LFM signals out step by step. The merit of this new method is validated by an illustrative example in low Signal-to-Noise-Ratio (SNR) condition.
文摘将不同长度线性调频(Linear Frequency Modulation, LFM)信号装入矢量信号源,其载波频率设置为中频,分别采样其输出的不同长度的LFM信号,对输出的LFM信号进行脉冲压缩Matlab仿真处理。实验表明,在采样频率及输出幅度相同的条件下,102.00μs脉冲内LFM信号仿真处理后的信噪比和旁瓣抑制比,相较3.00μs的指标提高了13.35 dB和4.61dB。进一步说明了由组合脉冲组成的LFM发射波形信号,其脉压体制雷达存在近距离回波比远距离回波差问题。提出了一种复杂海洋环境下多目标探测方法,对海用脉压体制雷达真实回波性能进行了改善和提升。
文摘针对多分量线性调频信号存在重叠、漏检现象,导致波达方向的估计存在较大误差问题,提出多分量线性调频信号分数阶傅里叶域量纲归一化方法。首先给出了多分量LFM信号的阵列模型,讨论了阵列模型信号时频坐标系进行量纲归一化。通过对相干环境下分数阶傅里叶域进行量纲归一化操作,提高多分量信号在分数阶傅里叶域的分辨能力,保证信源数目估计的准确性。仿真结果表明该方法正确的识别信源组数,提高多分量信号波达方向估计精确度,信噪比低于-4 d B的信号抗干扰能力明显增强。
