Power, Rate and Location Control for Multi-User Ultra-Wideband Communication (Multi-User UWB Communication)

• Applicant: Professor Dr. Rudolf Mathar
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: from 2006 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 23650813

• Final Report Year: 2011

Final Report Abstract

In the present project, multi-user impulse radio ultra-wideband (IR-UWB) systems are investigated. Due to low energy consumption and low complexity transceiver hardware UWB technology is especially of interest for wireless sensor networks with battery operated sensor nodes. As an important application class for wireless sensor networks distributed detection is considered. In distributed detection local detection results of multiple sensor nodes about the absence or presence of an object or event are combined to obtain a global decision with high reliability. In this project, UWB sensor networks for distributed detection are analyzed and methodologies and algorithms to optimize such systems under different aspects are derived. The proposed solutions build upon aspects from signal processing, transceiver design, and resource allocation, all adapted to distributed detection. Adapting the transmission power is a basic means to control the performance of UWB networks. We present a general approach that minimizes the transmission power given quality of service requirements of all nodes. The number of computations that is required to find the optimal power levels can be significantly reduced if the network topology is taken into account. Efficient solutions are derived for the parallel, the serial, and the tree topology. As an alternative, algorithms are investigated that perform the computation of the power levels in a distributed manner. The methods for power control are used to optimize distributed detection in UWB sensor networks where multiple access to the channel is realized by pseudorandom time hopping. The objective is to minimize the global probability of detection error given a total budget of transmission power. For the serial and the tree topology additional methods are required that determine the configuration of the network. For this purpose, application-specific routing and clustering algorithms are developed. To decrease the hardware complexity of the sensor nodes several strategies are proposed which allow for a low complexity implementation while maintaining as much control functionality as possible. Finally, two experimental case studies are presented that illustrate the wide range of possible applications for UWB sensor networks and that validate several concepts developed in this project by sensor measurement data. The first case study is a UWB-radar based sensor network for distributed target detection and the second case study is an implementation of cooperative spectrum sensing in cognitive radio where the signaling channel is realized by UWB technology. In future work, sensor nodes with integrated radar and communication capabilities will be analyzed and a joint optimization of these two tasks will be performed.

Publications

• “Topology generation and power assignment in IR-UWB networks,”. In: Proc. IEEE Int. Symp. Wireless Commun. Syst. (ISWCS), Oct. 2007, pp. 277–281
  D. Bielefeld and R. Mathar
  
• “Distributed power and topology control for IR- UWB sensor networks,”. In: Proc. IEEE Int. Symp. Wireless Commun. Syst. (ISWCS), Oct. 2008, pp. 578–582
  D. Bielefeld and R. Mathar
  
• “Power-aware distributed detection in IR-UWB sensor networks,”. In: Proc. IEEE Sensor Array and Multich. Signal Process. Workshop (SAM), July 2008, pp. 261–265
  D. Bielefeld, G. Fabeck, and R. Mathar
  
• “Theoretical analysis of the energy capture in strictly bandlimited ultra-wideband channels,”. In: Proc. IEEE Int. Symp. Wireless Commun. Syst. (ISWCS), Oct. 2008, pp. 229–233
  G. Böcherer, D. Bielefeld, and R. Mathar
  
• “Analysis and control of IR-UWB sensor networks for distributed detection applications,”. Frequenz - J. RF-Eng. Telecommun., vol. 63, no. 9–10, pp. 205–209, Nov. 2009
  D. Bielefeld, G. Fabeck, and R. Mathar
  
• “Power-aware distributed target detection in wireless sensor networks with UWB-radar nodes,”. In: Proc. IEEE Int. Radar Conf., May 2010, pp.842–847
  D. Bielefeld, R. Mathar, O. Hirsch, and R. S. Thoma
  
• “Routing path selection and power allocation for distributed detection in wireless sensor networks,”. In: Proc. IEEE Veh. Technol. Conf. Spring (VTC-Spring), May 2010, pp. 1–5
  D. Bielefeld, G. Fabeck, and R. Mathar