Iterative Correction of Frequency Response Mismatches in Time-Interleaved ADCs: A Novel Framework and Case Study in OFDM Systems

In this paper, the authors study a versatile iterative framework for the correction of frequency response mismatch in time-interleaved ADCs. Based on a general time varying linear system model, they establish a flexible iterative framework, which enables the development of various efficient iterative correction algorithms. In particular, they study the Gauss-Seidel iteration in detail to illustrate how the correction problem can be solved iteratively, and show that the iterative structure can be efficiently implemented using Farrow-based variable digital filters with few general-purpose multipliers. Simulation results show that the proposed iterative structure performs better than conventional compensation structures. Moreover, a preliminary study on the BER performance of OFDM systems due to TI ADC mismatch is conducted.