A Low - Complexity 128 - Point Mixed - Radix FFT Processor for MB - OFDM UWB Systems Sang - In Cho and Kyu -

© 2010 Sang-In Cho et al. 1 In this paper, we present a fast Fourier transform (FFT) processor with four parallel data paths for multiband orthogonal frequency-division multiplexing ultrawideband systems. The proposed 128-point FFT processor employs both a modified radix-2 algorithm and a radix-2 algorithm to significantly reduce the numbers of complex constant multipliers and complex booth multipliers. It also employs substructure-sharing multiplication units instead of constant multipliers to efficiently conduct multiplication operations with only addition and shift operations. The proposed FFT processor is implemented and tested using 0.18 μm CMOS technology with a supply voltage of 1.8 V. The hardwareefficient 128-point FFT processor with four data streams can support a data processing rate of up to 1 Gsample/s while consuming 112 mW. The implementation results show that the proposed 128-point mixed-radix FFT architecture significantly reduces the hardware cost and power consumption in comparison to existing 128-point FFT architectures.