Blind timing skew estimation based on spectra sparsity and all phase FFT for time-interleaved ADCs

A time-interleaved analog-to-digital converter (TIADC) is a promising solution for high speed and high resolution ADC. Blind timing skew estimation (TSE) is one of its key techniques for implementing online timing skew mismatch compensation digitally. Assuming the input signal of the TIADC is of spectral sparsity, in this paper, an efficient blind TSE algorithm is developed by employing the all phase Fast Fourier Transform (ApFFT) technique to obtain the accurate phase spectral estimation, which results in the ApFFT-SS-BLTSE algorithm. Experimental results show that, compared to the SS-BLTSE algorithm in [1], the proposed ApFFT-SS-BLTSE algorithm requires less computational cost and is able to offer high TSE accuracy for both narrow and wideband source signals in the presence of additive noise.