Flexible and reliable transmission techniques for scale-free UWB system

The speedy dissemination of digital consumer electronics devices within home and personal area causes increments of multimedia communication and advent of entertainment networking. This feature of communication requires variable data-rate and reliable transmission. In order to meet the various demands, in this paper, the multiband orthogonal frequency division multiplexing (MBOFDM) ultra-wideband (UWB) system by exploiting a time domain spreading factor and multiple-access scheme is proposed for variable data-rate transmission from 20kbps to 960Mbps in wireless communication. This article presents the basic structure and main functions of the variable data-rate (VR)-UWB system. With an emphasis on a proposed idea, we address the multiple-access in MB-OFDM system and apply adaptive bit allocation schemes to OFDMA system. It is shown in this article that scale-free UWB can accept multiple users and provide variable data-rate as well as support reliable transmission, while most conventional studies focus on the fixed rate transmission. The proposed system will be promising solution in ubiquitous environment to support multimedia traffic with various rates.