基于迭代更新策略的快速高精度频率估计方法  

Fast and accurate frequency estimation with a gradient-based iterative algorithm

作　　者：高志峰[1,2] 彭喜元[1] 彭宇[1] 

机构地区：[1]哈尔滨工业大学自动化测试与控制研究所,哈尔滨150080 [2]山东大学机电与信息工程学院,山东威海264209

出　　处：《振动与冲击》2015年第14期16-20,共5页Journal of Vibration and Shock

基　　金：国家自然科学基金(61304142;61305130)

摘　　要：基于滤波器组的谱估计方法用于信号频率估计频率虽分辨率高,但滤波器组中心频率格点划分缺乏先验知识,谱峰搜索过程存在计算复杂、信号不匹配问题。基于MVDR(Minimum Variance Distortionless Response)谱构造指标函数,将谱峰搜索问题等价为标量指标函数局部极小值问题求解,通过构造一组最速下降方向及自适应步长对极值频率迭代更新,实现对信号频率的直接估计。新算法不仅回避中心频率点组划分及传统的谱峰搜索,且有效缓解信号不匹配,估计精度、计算效率更高。对单成分信号频率估计精度与计算量进行新算法与现有算法的性能比较,并用于多成分信号频率估计。Nonparametric spectral estimation algorithms were applied to frequency estimation for their significant performance.To avoid the signal mismatch problem and to improve the frequency estimation accuracy,a new iterative algorithm was presented based on the minimum variance distortionless response （MVDR）spectrum.With given initial frequency,searching directions and adaptive steps were derived to update the frequency sequence,which converges to a local spectral peak as the scalar gradient function goes to zero.Without the spectral peak searching on predefined analysis frequency grids,the computation is saved.The proposed algorithm was also applied to multiple component frequency estimation with carefully selected initial frequencies.

关 键 词：频率估计 迭代算法 自适应步长 MVDR 

分 类 号：TP202.4[自动化与计算机技术—检测技术与自动化装置]