Spectral Estimation of Wide-band Noise in Delta-Sigma Modulators

Spectral leakage is a well-known phenomenon induced by the windowing process and usually revealed in the frequency domain. Scientific literature has deeply investigated the spectral leakage of narrow-band components. However, the problem of windowing a wide-band colored noise has not been fully characterized, yet. In this paper the effect of the windowing process on the estimate of the in-band DeltaSigma -shaped-quantization noise power spectral density (PSD) is investigated. The reported analysis holds for any modulator order and for any kind of real and symmetric window. Moreover, an a-priori criterion for designing optimal window that reduces shaped noise spectral leakage and for choosing the minimum number of acquired samples to be employed is derived