Print This Page

Sub Working Group 2.1 - RF Aspects in UWB Communication and Localisation

Chairman: Dr. Grzegorz Adamiuk, University of Karlsruhe, Germany

Ultra Wideband is an emerging technology that offers a variety of new applications. Its existence began with the release by the FCC of the UWB frequencies from 3.1 GHz to 10.6 GHz with the maximal allowed power spectral density of -41.3 dBm/MHz for license free usage. UWB-Systems offers new possibilities and alternatives to the common wireless systems, especially on a short distance. A huge bandwidth (7.5 GHz) of the signal allows for a very high channel capacity in a communication link or very accurate localization possibilities. However this technology needs strong research activities before handed over to the end-user.

The main focus of this group is on the characterization and modeling of UWB radio channel, antennas and analog frontend. Since UWB is originally a pulse-based (i.e. time domain-based) technique, new parameters characterizing the mentioned issues in the time domain can be defined. It would extend a typical narrow-band, frequency domain description of a wireless system, which would give better impression of the effects ruling an UWB signal transmission.

On the certain fields the group tries to solve the following problems:

  • UWB Channel: the optimization of the existing as well as the design of new stochastic and deterministic simulation approaches is investigated. The number of potential UWB applications in communication and thus the number of potential environments is constantly growing. Although the stochastic IEEE 802.15.3a/4a channel models characterize some common scenarios, the number of measurements used for the model parameterization is still relatively low and the available models do not cover the whole interesting frequency band and all possible scenarios. Thus channel measurements as well as improved stochastic UWB channel models are of great interest for the development of further UWB systems.As deterministic channel models reflect the geometry of the considered scenario, they are inevitable for the design and optimization of localization and imaging algorithms. Research on computational efficient full wave methods and on optimization of the ray tracing techniques (e.g. inclusion of the diffuse scattering or implementation in time domain) in different environment (e.g. indoor, car etc. ) is incorporated in the work of this SWG.
  • UWB Antennas: usually the shape of an antenna impulse response varies over the angle and additionally the radiation properties change over the UWB frequency band. These non-ideal effects reduce the accuracy of those localization algorithms that are based on the estimation of the time of arrival of the multi-path components. The SWG 2.1 deals with the design of dedicated constant gain (in frequency and azimuth) UWB antennas. Other antenna concepts to be investigated are: high gain UWB antenna arrays, planar and dual polarized antenna arrays, modeling of mutual coupling effects, etc.
  • UWB Analog Frontend: the optimal UWB transmitter/receiver architecture is still a current topic of research. On the one hand, in order to be successful on the market, low cost UWB frontends are required. On the other hand, low cost products use generally low-end, non-ideal analog components that might be an error source for UWB applications. The influence of the non-ideal behavior of the analog components on the performance of UWB localization and communication systems is studied within this SWG. Additionally the development of possible compensation techniques could be proposed.

Furthermore the contributions from the field of UWB applications are highly welcome. They reveal new ideas of implementation possibilities of UWB, where its special properties are in demand.

This group is also addressed to the researchers that work on non-RF UWB topics (like localization algorithms, tracking algorithms, ad-hoc networks, cooperative notes, digital receiver optimization & implementation, recognition of unknown objects and coding strategies) having RF-problems. An experience of the RF-engineers and ideas from other fields can lead to mutual benefits.