Oversampling and Noise Shaping

Abstract

Analog-to-digital and digital-to-analog conversion are important functions that greatly determine the quality of the signal processing chain. We showed in Chap. 4 that a certain effort is required for filtering in the continuous-time domain in order to avoid errors in the transition process from the analog to the discrete-time world and vice versa. The complexity of the involved filters increases more, the better the frequency range 0 ? |?| < ?_s/2, the baseband, is to be utilised and the higher the requirements are with respect to the avoidance of signal distortion. The resolution of the converters determines the achievable signal-to-noise ratio (SNR). Each additional bit improves the SNR by about 6 dB. The costs of the converters, however, increase overproportionally with the resolution.