A Low-Complexity 128-Point Mixed-Radix FFT Processor for MB-OFDM UWB Systems

Date Added: Feb 2010
Format: PDF

Ultra-WideBand (UWB) systems supporting various data rates from tens of Mb/s to hundreds of Mb/s are very suitable for application to short range wireless communications because they can share the frequency band with existing narrowband systems. One of the candidate schemes for the high-speed UWB PHYsical layer (PHY) is a MultiBand Orthogonal Frequency-Division Multiplexing (MB-OFDM) scheme. One OFDM symbol in the MB-OFDM UWB system consists of 128 subcarriers and 37 zero samples. The 128 subcarriers are composed of 100 data subcarriers, 12 pilot subcarriers, 10 guard subcarriers, and 6 null subcarriers. Therefore, the Fast Fourier Transform (FFT) processor of the MB-OFDM UWB system conducts a 128-point FFT operation, where the sampling frequency is 528 MHz and the subcarrier frequency spacing is 4.125 MHz.