A class of reconfigurable and low-complexity two-stage Nyquist filters

• Provides a method to design two-stage reconfigurable Nyquist filters.
• Results in filters which have a low arithmetic complexity.
• Proposes a design method which is applicable to a wide range of filter specifications.
• Illustrates these facts by the help of various design examples.

This paper introduces a class of reconfigurable two-stage Nyquist filters where the Farrow structure realizes the polyphase components of linear-phase finite-length impulse response (FIR) filters. By adjusting the variable predetermined multipliers of the Farrow structure, various linear-phase FIR Nyquist filters and integer interpolation/decimation structures are obtained, online. However, the filter design problem is solved only once, offline. Design examples, based on the reweighted ℓ1-norm minimization, illustrate the proposed method. Savings in the arithmetic complexity are obtained when compared to the reconfigurable single-stage structures.