A low clock frequency FFT core implementation for multiband full-rate ultra-wideband (UWB) receivers

Abstract

This paper discusses the design, implementation and synthesis of an FFT module that has been specifically optimized for use in the OFDM based multiband UWB system, although the work is generally applicable to many other OFDM based receiver systems. Previous work has detailed the requirements for the receiver FFT module within the multiband UWB ODFM based system and this paper draws on those requirements coupled with modern digital architecture principles and low power design criteria to converge on our optimized solution particularly aimed at a low-clock rate implementation. The FFT design obtained in this paper is also applicable for implementation of the transmitter IFFT module therefore only needing one FFT module in the device for half-duplex operation. The results from this paper enable the baseband designers of the 200 Mbit/sec variant of multiband UWB systems (and indeed other OFDM based receivers) using system-on-chip (SoC), FPGA and ASIC technology to create cost effective and low power consumer electronics product solutions biased toward the very competitive market.