Correcting Timing Mismatch of Interleaved ADCs Using DCT

Abstract

Interleaved ADCs are used to increase sampling rate of available existing ADCs. By utilizing M ADCs, sampling rate can be increased by a factor of M. Interleaving of ADCs results in timing mismatch that causes nonuniform sampling. Timing mismatch correction in the frequency domain is considered in this paper. For a stationary signal the entire length of the nonuniformly sampled signal is transformed and timing mismatch is corrected in the frequency domain. Using the inverse Fourier transform, the uniformly sampled signal is reconstructed. The longer the signal, the better the performance in terms of correction. However, for a long signal long delay is required for correction. In image compression DCT is used for small blocks of an image. In this paper DCT is used to correct timing mismatch. Only M-point DCT is used for correction to minimize the delay. The experimental results show that the timing mismatch correction using DCT performs better than the DFT method.