Subband Architecture for Hybrid Filter Bank A/D Converters

Hybrid filter bank (HFB) A/D converters (ADCs) are a candidate to realize the wideband ADC for future telecommunication systems. The classical HFB-based ADCs are simulated in both time and frequency domains using simply-realizable analog filters in this paper. The high sensitivity of HFBs to realization errors of an analysis filter bank is studied and it is shown that a new HFB architecture is necessary to employ the blind techniques for correcting the analog imperfections. Using the discrete-time model of HFB, a multiple-input multiple-output (MIMO) model is proposed for the HFB so that a new architecture called subband HFB-based ADC is obtained. The subband HFB ADC not only leads to a better resolution but is less sensitive to realization errors than the classical case. Besides, a linear-time invariant (LTI) system represents the input-output relation of subband HFB without any spectral overlapping in contrary to the classical HFB. Thus, blind techniques may be used for correcting the realization errors in the subband HFB.