Performance evaluation of MB-OFDM and DS-UWB systems for wireless personal area networks

Ultra-wideband (UWB) radio has been proposed for physical layer standard of the future high-speed wireless personal area networks (WPANs). One proposal is referred to as multi-band orthogonal frequency division multiplexing (MB-OFDM), and the other is direct-sequence ultra-wideband (DS-UWB). In this paper, we evaluate the performance of these physical layers as proposed to the IEEE 802.15 Task Group 3a. Specifically, we evaluate and compare the 10% outage frame error rate (FER) versus transmit-receive distance for the two systems using standard UWB channel models. In an AWGN channel, the two approaches yield essentially the same performance. In fading channels, the MB-OFDM system is shown to outperform the DS-UWB system for the assumed receiver structures. However, the relative performance ranking turns primarily on the signal processing complexity of the receiver, especially at high rates. Furthermore, the DS-UWB system is found to be more robust to imperfect channel estimation than the MB-OFDM system.