On the sensitivity of digital predistortion to impairments of time-interleaved A/D converters

The need for high sampling rates in the feedback path of the digital adaptive predistortion for power amplifier linearization usually limits its use to the cases with sufficiently narrow bandwidth, that is contradictory to the envisaged signal bandwidth widening in the future communication systems. One of the solutions to relax the requirements on A/D converters in the predistortion system is to use them in a time-interleaved manner, but the imprecise time alignment, unequal gain or signal offset in the individual A/D sections may reduce the linearization performance. The goal of this paper is to investigate the potential effect of such impairments, present in the time-interleaved A/D conversion concept, to the performance of digital predistortion linearizer applied to typical filter-based multicarrier modulation.