基于二维幅值谱的正弦信号频率估计  

Sinusoid Signal Frequency Estimation Based on Two-dimensional Amplitude Spectrum

作　　者：韩峰[1] 田敏[1] 徐刚[1] 

机构地区：[1]内蒙古工业大学机械学院,内蒙古呼和浩特010051

出　　处：《现代电子技术》2010年第13期103-106,共4页Modern Electronics Technique

摘　　要：信号中含有噪声或非整周期截断时发生的频谱泄漏是导致正弦信号频率估计精度不高的主要原因。针对这一问题,从扩展信号频谱表征方式出发,将经典幅值谱扩展至不受频谱泄漏制约、表现力更强、可读性更好的二维幅值谱。与经典幅值谱相比,二维幅值谱除包含信号的频率个数、幅值信息外还包含了易于获取的周期信息,且具有一定的抗噪性,在信噪比低至-10 dB时仍有较好表现力。提出一种估计方法,先从二维幅值谱中估计出信号的周期T,然后根据信号采样频率、信号频率、以及信号周期T之间的定量关系完成信号的频率估计。实验结果证明了该方法的有效性。基于二维幅值谱的正弦信号频率估计方法为正弦信号的频谱估计提供了一种新思路。The spectrum leakage producing as the signal has noise or non-integer period truncation is a principal reason of reducing the accuracy of the sinusoid signal frequency estimation. The typical amplitude spectrum of signals is expanded from one dimension to two dimension for solving that problem. The 2D amplitude spectrum shows more useful information of signals and is not limited by the signal integer period truncation. It contains the number of signal frequencies, amplitude information and easily obtained periodic information. Because of that, more useful information can be obtained from 2D spectrum than 1D＇s. The 2D amplitude spectrum still has noise cancelling performance when SNR decreases to -10 dB. A new method to accomplish the frequency estimation of the signal according to the quantitative relation among sampling frequency, signal frequency and signal period T which is obtained by the estimation of 2D amplitude epectrum is proposed. It has an agreeable accuracy and good robustness.

关 键 词：DFT 二维幅值谱 频率估计 正弦信号 

分 类 号：TN911[电子电信—通信与信息系统]