Correcting the Effects of Mismatches in Time-Interleaved Analog Adaptive FIR Equalizers

Analog discrete-time finite-impulse-response (FIR) filters have been used as equalizers in digital communication receivers. For high speed applications, an FIR equalizer can be implemented using parallel sample-and-holds (S/Hs) and time-interleaved equalizer channels. Mismatches among the parallel S/Hs degrade the equalizer performance. This paper addresses mismatches of DC offsets, gain errors, sample-time errors, and bandwidths in the S/Hs. It is shown that having a different set of adapted coefficients in each equalizer channel can reduce the effects of mismatches. Simulation results are presented for different communication channels.