High-throughput and compact reconfigurable architectures for recursive filters

This study presents various high-throughput reconfigurable architectures and their hardware implementation characteristics for infinite impulse response (IIR) filters. It is known that finite word length effects can be alleviated, to some extent, by realising a high-order IIR filter using the cascade of lower-order filter sections. The authors utilise the cascade structure of the first-order and second-order filters and apply a set of optimisation techniques, such as cutset retiming, look-ahead transformations, and interleaving for high-throughput realisations of IIR filters. Since the cascade structure may require a relatively large number of computational resources and storage elements, which depends linearly on the number of sections, the authors also present a filter processor architecture for the compact implementation of IIR filters. Filter architectures are developed in the fully parameterisable fixed-point representation and verified against their synthesisable Verilog descriptions. The authors present the implementation results of the transformed filter architectures on a Xilinx Virtex-7 field-programmable gate array (FPGA). To the best of their knowledge, this is the first presentation of various high-throughput and compact IIR filter architectures and their FPGA implementation characteristics.