A Novel FFT Processor for OFDM UWB Systems
Zhongjun Wang, Lee Guek Yeo, Wenzhen Li, Yanxin Yan, Yujing Ting, Masayuki Tomisawa · 2006
In this paper, we present a novel mixed-radix Fast Fourier Transform (FFT) architecture for orthogonal frequency division multiplexing (OFDM) ultra wide-band (UWB) systems. The proposed architecture is simply comprised of two stages. The first stage involves two sliding radix-4 butterflies. The second stage consists of four parallel processing units. These processing units are formed with an identical pipelined radix-2 structure. This unique arrangement has proved to be silicon implementation friendly. Important to note that, with adoption of the proposed architecture, about 25% power saving can be achieved by simply turning off two processing units in the second stage, when the input data are complex conjugate symmetrical.