A Measurement Method of Frequency Response Characteristics Test Based on Chirp Signal at Low SNR
WEI Lie-jiang1, LI Xu-fang1, WANG Lin1, DONG Wan-yu1, MENG Li2
1.School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China;
2.Gansu Institute of Metrology, Lanzhou, Gansu 730070, China
Abstract：A method using band-pass filter and wavelet packet transform to pre-treat signal and then using FFT analysis and treatment to get frequency response diagrams is described. This method is better to solve the problems that frequency characteristic test of the system is under low SNR, and reduce hardware requirements of acquisition system in the test. The research show that when SNR is very low and even negative 20 dB value, the amplitude-frequency characteristic that accuracy is not less than 1dB and phase frequency response curve that accuracy is not less than 3°can be obtained for frequency bands that is below the cutoff frequency, which fully meet the system performance evaluation and controller design application requirements.
魏列江, 李旭方, 王 霖, 董万玉, 孟 犁. 低信噪比下基于Chirp信号的频率特性测试方法[J]. 计量学报, 2014, 35(3): 272-275.
WEI Lie-jiang, LI Xu-fang, WANG Lin, DONG Wan-yu, MENG Li. A Measurement Method of Frequency Response Characteristics Test Based on Chirp Signal at Low SNR. Acta Metrologica Sinica, 2014, 35(3): 272-275.
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2014, Vol. 35 
