基于滑动FrFT瞬时频率估计的VCO非线性度检测方法
为提高现有方法在精度、抗噪性和实时性方面的性能，提出一种基于滑动分数阶傅里叶变换（Fractional Fourier Transform，FrFT）瞬时频率估计的压控振荡器（Voltage Controlled Oscillator，VCO）非线性度检测方法。首先通过滑动重叠分段VCO的输出信号减少频谱泄漏，提高抗噪性；然后利用滑动FrFT在分析非平稳信号尤其是线性调频信号时的独特优势，检测出分段信号中间时刻点的频率，重点阐述了通过黄金分割和混沌优化相结合的方法快速搜索滑动Fr丌的最佳分数阶比，确保算法实时性能的过程；最后，通过中间时刻点频率的三次样条插值以提高精度。仿真结果表明，与现有方法...
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| Published in | 电测与仪表 Vol. 52; no. 14; pp. 86 - 92 |
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| Main Author | |
| Format | Journal Article |
| Language | Chinese |
| Published |
后勤工程学院,重庆,401311
2015
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| Subjects | |
| Online Access | Get full text |
| ISSN | 1001-1390 |
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| Summary: | 为提高现有方法在精度、抗噪性和实时性方面的性能，提出一种基于滑动分数阶傅里叶变换（Fractional Fourier Transform，FrFT）瞬时频率估计的压控振荡器（Voltage Controlled Oscillator，VCO）非线性度检测方法。首先通过滑动重叠分段VCO的输出信号减少频谱泄漏，提高抗噪性；然后利用滑动FrFT在分析非平稳信号尤其是线性调频信号时的独特优势，检测出分段信号中间时刻点的频率，重点阐述了通过黄金分割和混沌优化相结合的方法快速搜索滑动Fr丌的最佳分数阶比，确保算法实时性能的过程；最后，通过中间时刻点频率的三次样条插值以提高精度。仿真结果表明，与现有方法相比，文中方法在信噪比为-5dB-5dB的实验环境下具有更好的性能，且计算量适中。 |
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| Bibliography: | To improve the precision, anti-noise and the real-time performance of VCO non-linearity detection methods presently, a new method based on sliding Fractional Fourier Transform （FrFT） for instantaneous frequency estimation was proposed. Firstly, this method overlapped sliding to intercept the estimated signal to improve the anti-noise per- formance, and then got middle-time＇ instantaneous frequencies of all intercept signals by sliding FrFT, and improved the real-time performance by golden section and chaos optimization method searching the optimal order of sliding Fr- FT. Finally, it got a more precise instantaneous frequency by cubic splines interpolation between those middle-time＇ instantaneous frequencies. Experiment results show the proposed method has better performance than existing methods at Signal Noise Ratio （SNR） from -5dB to 5dB with a suitable calculation. 23-1202/TH Xiao Wei, Mo Zhengjun, Xu Wei （ Logistical Engineering University, Chongqing 401311, China） instantaneous frequency estimation, non-li |
| ISSN: | 1001-1390 |