相减策略的含噪多频实信号频率估计算法  

Frequency estimation algorithm of multi-frequency real signals with noise based on Subtraction Strategy

作　　者：陈鹏[1,2] 刘春华[2] 沈廷鳌 乐开白[2] CHEN Peng;LIU Chunhua;SHEN Ting’ao;YUE Kaibai(State Key Lab of Aerodynamics,China Aerodynamic Research and Development Center,Mianyang 621000,China;Facility Design and Testing Technology Institute,China Aerodynamic Research and Development Center,Mianyang 621000,China;Petroleum Department,Army Logistics University,Chongqing 401311,China)

机构地区：[1]中国空气动力研究与发展中心空气动力学国家重点实验室,四川绵阳621000 [2]中国空气动力研究与发展中心设备设计与测试技术研究所,四川绵阳621000 [3]陆军勤务学院油料系,重庆401311

出　　处：《振动与冲击》2022年第19期152-156,178,共6页Journal of Vibration and Shock

基　　金：空气动力学国家重点实验室基金(SKLA2019040202);重庆市自然科学基金(cstc2019jcyj-msxmX0628);重庆市教委科技项目(KJQN202112902)资助。

摘　　要：为抑制频谱泄漏对多频实信号频率估计的影响,提出一种新的频率估计算法。利用FFT法和相减策略对采样信号进行处理,逐步得到各分量的频谱最大值索引,以及各分量频谱偏移量和复幅值粗略值;构造包含所有非待估计频率分量的参考信号,利用相减策略从采样信号中减去参考信号,得到待估计的单频复信号,并对其频谱进行两点插值计算,得到该分量较精确的频谱偏移量和复幅值;然后,通过相减策略和频谱分析,逐步得到所有分量较精确的频谱偏移量和复幅值;通过迭代计算得到各分量精确的频率估计值。同时,可得到各分量精确的幅值和初相位。在无噪声、不同频率间隔等条件下进行了频率仿真试验。结果表明:所提算法有效抑制了频谱泄漏的影响,提高了多频实信号的频率估计精度,频率估计值的均方误差比其他优秀算法更靠近克拉美罗下限。Here,to suppress effects of spectrum leakage on frequency estimation of multi-frequency real signals,a new frequency estimation algorithm was proposed.Firstly,FFT method and subtraction strategy were used to process sampled signals,and the maximum value index of each component spectrum,rough values of each component spectral offset and complex amplitude were obtained step by step.Secondly,a reference signal containing all frequency components not to be estimated was constructed,and this reference signal was subtracted from the sampled signal by using the subtraction strategy to obtain the single frequency complex signal to be estimated,and the 2-point interpolation calculation was performed for its spectrum to obtain this complex signal’s more accurate spectral offset and complex amplitude.Then,through subtraction strategy and spectral analysis,more accurate spectral offsets and complex amplitudes of all components were gradually obtained.Finally,the accurate frequency estimation of each component was obtained using iterative calculation.At the same time,the accurate amplitude and initial phase of each component were obtained.Frequency simulation experiments wereconducted under conditions of no noise and different frequency intervals.The resultsshowed that the proposed algorithm can effectively suppress effects of spectrum leakage,and improve the frequency estimation accuracy of multi-frequency real signals;mean square errors of frequency estimation valuesobtained using the proposed method are closer to Cramer-Rao lower bound than those obtained using other excellent algorithms.

关 键 词：频率估计 相减策略 频谱泄漏 多频实信号 

分 类 号：TH814[机械工程—仪器科学与技术]