Portable low-power IR-UWB system

Indoor environments are typically complex wireless propagation channels with numerous multi-paths created by closely spaced scattering objects. The ability to resolve these multi-paths is very important for good ranging resolution and positioning accuracy. Impulse-Radio Ultra-Wideband (IR-UWB) is a promising technology to fulfill these usage requirements in indoor cluttered environment. A portable low-power IR-UWB system for indoor channel characterization and time of arrival ranging measurements is presented in this paper. The system consists of battery powered transmitters and a four channel receiver array system powered from the USB port of a notebook computer. A novel repetitive coding and stroboscopic sampling technique are used to reduce power consumption while maintaining precise ranging using time of arrival based technique. The repetitive coding also enables data communication capability through thecoding also enables data communication capability through the same wireless channel. Power saving and precision ranging is achieved by optimization of the circuit design for ultra short pulses as well as system architecture and operation. The transmitted pulse is captured by low-cost energy-detection receivers with analogue to digital converters running at around 3.2MHz rate.