ADC Nonlinearity in Wireline Receivers

The use of high-order modulation for wireline communication has both increased linearity requirements and precipitated the use of ADC-based receivers. Ironically, a major source of nonlinearity in such wireline receivers is the ADC itself. The characteristics of signals arriving at a wireline receiver front-end are unlike the single- or two-tone sinusoidal signals usually used to measure ADC nonlinearity. Hence, the traditional ADC performance metrics such as “effective bits” of resolution should be revisited. This presentation will quantify and model nonlinearities in ADCs for wireline links, and present methods for correcting them.