On a filter bank correction scheme for mitigating mismatch distortions in time-interleaved converter systems

This paper presents a multirate filterbank architecture that mitigates the distortion caused by non-ideal samplers in a time-interleaved system. Closed form fractional delay filters with finite impulse response (FIR) and infinite impulse response (IIR) type are employed to model the behaviour of the non-ideal converters. Based on a polyphase description of the system, the reconstruction filters are derived for the IIR case, which can be regarded as a generalization of the FIR design scheme. Furthermore, the achieved performance of filter banks for various fractional delay filters is compared. To investigate the numerical robustness, the impact of limited coefficient lengths on different figures-of-merit was explored. Finally, the reconstruction of a non-uniformly sequence was used as an example to verify the reconstruction scheme.