Multiple-access capability of DS-UWB and multi-band OFDM schemes for IEEE802.15.3a

Abstract

The demand for high data rate transmission in mobile wireless communications is growing rapidly. Apart from the traditional DS-UWB (Direct Sequence Ultra Wide Band), Multi-band Orthogonal Frequency Division Multiplexing (OFDM) has attracted diverse interest as a modulation technique for short range wireless data communications described in the IEEE 802.15.3a physical layer proposal. In this paper, two multiple access schemes for uplink system in a multi user environment are studied with respect to their error performance. Investigation covers two schemes, namely an uncoded orthogonal frequency division multiplexing (OFDM) based code division multiple access scheme (OFDM-CDMA), and an uncoded direct sequence code division multiple access (DS-CDMA) scheme. In both schemes, Maximum Ratio Combining is applied at the receiver. The performance of the two schemes is compared considering different channel modes which is important for the later system design. The analytical results are confirmed by the simulation results which suggest OFDM-CDMA outperforms DS-CDMA under slow fading multi-path environment.