A new technique for adaptive frequency estimation and tracking
A new technique for adaptive frequency estimation and tracking
复制标题
自适应频率估计和跟踪的新技术
DOI：
10.1109/tassp.1987.1165146
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
D. Hush
中科院分区：
文献类型：
--
作者：
D. Etter;D. Hush
本文提出了一种在噪声中估计正弦信号频率的新方法。标准技术通常从自相关函数的估计或从滤波器模型估计正弦曲线的频率。这些技术需要大量的样本来精确估计频率。此外，如果频率随时间变化，则每次估计更新都需要重新计算自相关或滤波器模型。在这种对应关系中，我们提出了一种新的技术，是基于一个可变的延迟元件。我们将表明，相应的误差表面是正弦曲线，并且误差函数的第一个最大值发生在未知正弦曲线的一半周期处。我们将开发一种基于梯度技术的算法来找到这个最大值，并从这个最大值直接计算频率估计。新算法在时域中工作，具有简单的自适应延迟更新计算。该技术已在模拟中进行了测试，信噪比低至1：10，具有优异的性能。算法的速度取决于从输入信号的功率的初始估计计算的收敛因子。由于该技术是自适应的，它也可以应用于跟踪时变频率。
A new technique is presented for estimating the frequency of a sinusoid in noise. Standard techniques typically estimate the frequency of a sinusoid from an estimate of the autocorrelation function or from a filter model. These techniques require a large number of samples for an accurate estimate of the frequency. Furthermore, if the frequency is varying with time, recomputation of the autocorrelation or filter model is necessary for each estimate update. In this correspondence, we present a new technique that is based on a variable delay element. We will show that the corresponding error surface is sinusoidal, and that the first maximum of the error function occurs at one-half the period of the unknown sinusoid. We will develop an algorithm that is based on gradient techniques to find this maximum, and from this maximum we directly compute the frequency estimate. The new algorithm works in the time domain with a simple adaptive delay update computation. The technique has been tested in simulations with signal-to-noise ratios as low as 1 : 10, with excellent performance. The speed of the algorithm depends on a convergence factor that is computed from an initial estimate of the power of the input signal. Since the technique is adaptive, it can also be applied to tracking a time-varying frequency.