Two channel TI-ADC for communication signals

Abstract

Time-interleaved analog-to-digital converters (TI-ADCs) offer a significant increase in the available sample rate of ADCs. Their performance is degraded by timing and gain mismatches. Most of the literature on mismatch estimation and correction in TI-ADCs is concentrated on low-pass converting baseband signals. This paper provides a semi-blind solution, for both timing and gain mismatches correction, in the digital data section of a two-channel TI-ADC for band-pass input signals. This is a realistic communications system scenario. Modern system designs lean towards having the ADC interface with intermediate frequency (IF) signal in the analog section of a digital receiver rather than the DC centered, analog down converted, in-phase and quadrature pair.