时域噪声引起频谱误差的估计方法

ESTIMATE METHOD OF SPECTRUM ERRORS RESULT FROM TIME DOMAIN NOISE

在模拟信号数字化的过程中,由于采样器固有噪声和取样脉冲抖动以及量化噪声等因素的影响,取样量化后的数字信号被噪声污染。对含有噪声的数字信号进行时频变换时,必然引起频谱误差。本文讨论如何利用误差功率估计由时域噪声引起的频谱误差问题。得出误差功率是频谱幅度误差的方差上限这一结论,该结论对评估数字信号的质量有参考价值。

In digitizing analogue signals, the digital signal is corrupted by the noise due to the inherent noise of the sampler and the quantizing noise. Spectrum errors will occur when the digital signal is transformed from time to frequency domaim. Estimate of the spectrum errors caused by the noise in time domain by using the errors power is discussed in this paper. And the conclusion that errors power is the upper limit of variance for spectrum amplitude errors is valuable to the evaluating of the quality of digital signal.