This article introduces a simple formula that provides the exact frequency of a pure sinusoid from just two samples of its discrete-time Fourier transform (DTFT). Even when the signal is not a pure sinusoid, this formula still works in a very good approximation (optimally after a single refinement), paving the way for the high-resolution frequency tracking of quickly varying signals or simply improving the frequency resolution of the peaks of a discrete Fourier transform (DFT).

中文翻译：

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超分辨率频段 [提示与技巧]

本文介绍了一个简单的公式，该公式仅根据离散时间傅里叶变换 (DTFT) 的两个样本即可提供纯正弦曲线的精确频率。即使信号不是纯正弦曲线，该公式仍然可以很好地近似（在一次细化后最佳），为快速变化信号的高分辨率频率跟踪或简单地提高峰值的频率分辨率铺平道路离散傅立叶变换 (DFT)。