In this study, the authors propose for the parameter estimation of chirp signals at low signal-to-noise ratios using the spectrum phase instead of the traditional temporal phase. First, the spectrum phase expression of chirp signals is derived, which demonstrates that the spectrum phase can be approximated as a quadratic function of the frequency. However, the spectrum phase is a wrapped phase modulo 2π, like the temporal phase. To obtain the unwrapped spectrum phase, the authors develop a robust phase unwrapping method and then perform linear regression on the unwrapped spectrum phase to obtain the estimates of the parameters. Finally, the estimates are refined by the O'Shea refinement strategy to reduce bias. The simulation results show that the proposed technique has a lower signal-to-noise ratio threshold and is less complex than the existing methods.

中文翻译：

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利用频谱相位进行线性调频信号的参数估计

在这项研究中，作者建议使用频谱相位而不是传统的时间相位来在低信噪比下进行线性调频信号的参数估计。首先，推导线性调频信号的频谱相位表达，这表明频谱相位可以近似为频率的二次函数。然而，频谱相位像时间相位一样，是模2π的包裹相位。为了获得展开的频谱相位，作者开发了一种鲁棒的相位展开方法，然后对展开的频谱相位执行线性回归以获得参数的估计。最后，通过O'Shea细化策略来细化估计值以减少偏差。