Exploitation of extra diversity in UWB MB-OFDM system

This paper describes and analyzes the performance of MB-OFDM (multi-band OFDM) UWB (ultra-wideband) system that is suggested as one of standards in IEEE 802.15 TG3a for UWB application. UWB channel model that has been contributed in IEEE 802.15 SG3a is a wideband channel model of 6 GHz bandwidth, so we modify it to have 3 subband channels that are obtained by filtering conventional UWB channel considering center frequency and bandwidth of each subband. We demonstrate performances of MB-OFDM system under the UWB channel by simulation and verify the frequency and time domain diversity gains. We also compare the performance of a proposed SFBC (space-frequency block code) MB-OFDM system with that of conventional MB-OFDM system and manifest the extra spatial diversity gain of MB-OFDM UWB system. Simulation results show SFBC MB-OFDM system outperforms conventional MB-OFDM system about 1.5 dB of E_b/N₀ at target BER of 10^-4.