Linear LMS Compensation for Timing Mismatch in Time-Interleaved ADCs

DAMIÁN MARELLI; KAUSHIK MAHATA; MINYUE FU

Orlando

Conferencia; Annual Conference of the IEEE Industrial Electronics Society (IECON); 2008

Institute of Electrical and Electronics Engineers (IEEE)

The time-interleaved architecture permits imple-menting high frequency analog-to-digital converters (ADCs) bymultiplexing the output of several time-shifted low frequencyADCs. An issue in the design of a time-interleaved ADC isthe compensation of timing mismatch, which is the differencebetween the ideal and the real sampling times. In this paperwe propose a compensation method which, as opposite to otherapproaches, do not make a bandlimited assumption on thesignal to be sampled. The proposed compensation is designedin a statistically optimal sense, to minimize the power of thereconstruction error in the samples, for a given input signalpower spectrum. Due to the non-bandlimited assumption, perfectreconstruction is not possible in general. However, if the inputsignal is bandlimited, the proposed method achieves perfectreconstruction, if no constraints are made in the order ofthe compensation. Simulation results show that the proposedcompensation outperforms the other methods, in terms of thereconstruction error power, for a given fixed compensation order,except for signal having large zero regions in their powerspectrum. A generalization of the proposed method solves thisdrawback, and will be addressed in a journal version.