Effects of ADC Integral Non-Linearity on Digital Transmission

This paper investigates the effects of Integral Non-Linearity (INL) on the performances of both A/D converters and Digital Communication Systems, which exploit Direct Digital Modulation. The performances of both PCM and Sigma-Delta converters affected by INL are considered and compared. Then, the effects of INL upon the BER performances of an OFDM system are evaluated and modeled. The accuracy of the theoretical model is discussed with respect to the ADC resolution and INL levels. It is shown that a multibit Sigma-Delta converter, operating at a low oversampling ratio, may outperform PCM converters.