Hybrid filter bank design and analysis

Wide-band, high resolution A to D converters (ADC) play a crucial role in future communications systems such as Software Defined Radio (SDR) or Cognitive Radio (CR). One approach to circumvent the limits of ADC technologies is to split the analog input signal into multiple components and then sample them with ADCs in parallel. Albeit that the two main parallel approaches, namely Time Interleaved (TI) and frequency splitting can be modeled using filter bank paradigm, each of these two architectures requires specific analysis for its design. Frequency splitting approach is implemented using Hybrid Filter Bank ADC (HFB ADC), which requires to have an output digital filter bank perfectly matched to the input Analogue Filter Bank (AFB). To this end, the analog transfer function together with an assumption of strictly band limited input signal is used to compute the digital filter bank. In this work we propose to drop the band limit assumption and show that the out of band input signal has to be taken into account when designing HFB.