Uncertainty Analysis of the Phase and RMS Value by Non-Coherent Sampling in the Frequency Domain

The determination of phase and RMS value belongs to the most important tasks of signal analysis in the frequency domain. Evaluating these parameters is frequently performed by the DFT (Discrete Fourier Transform) algorithm. In practice, signals are mostly sampled non-coherently. This leads to the well known effect called leakage, which results in spreading frequency spectral component energy to neighboring frequency lines. Therefore, time windows are used for leakage suppression. This paper introduces the problematic of uncertainty analysis of phase and RMS value computed from the DFT spectrum by non-coherent sampling using cosine windows. The analysis is aimed to investigate the influence of quantization noise.