Semester Thesis

Over the Air Demonstrator of an Ultra-Wideband WBAN Modem Design

In recent years, the demand for mobile devices has steadily increased. Tiny gadgets like cell phones and palms accompany everyday life and more and more data needs to be exchanged. A new field of interest are wireless body area networks (WBAN) where a net of nodes is placed directly on the human body or very close to it. The applications are manifold but often strongly depend on the battery life time. Therefore, power efficiency is very important and optimized power dissipation during data transmission essential.

Another topic of great contemporary importance are ultra-wideband (UWB) communication systems. On the one hand, this new technology allows high data rates. On the other hand, a different approach with a low duty cycle leads to an enormous reduction of power dissipation.

The UWB communications group at CTL merged the two topics and proposed an ultra low power system with respect to one specific WBAN application [1]. Focusing mainly on the receiver side, they developed a noncoherent energy based ultra-wideband impulse radio (UWB-IR) modem with a low duty cycle. The transmission side was not considered as detailed as the receiver side because it is assumed to dissipate much less power. During modem design, issues like radiation regulations, path loss, interference from other communication systems and multi access were considered. Modem parameters were optimized with respect to power dissipation. The overall transmission chain was implemented in Matlab. With this model, simulations were done to collect performance data, such as BER vs. transmit power plots.

This semester thesis aims at the simulation of the modem over the air by using several measurement devices and a control PC on which the Matlab model of the modem is run. In order to build the transmission chain, a familiarization with the measurement equipment is necessary. In a second step, a simple demonstration is set up to show the functional capability on a concrete example.

[1] F. Troesch, C. Steiner, T. Zasowski, T. Burger, and A. Wittneben. Hardware Aware Optimization of an Ultra Low Power UWB Communication System. 2007 IEEE International Conference on Ultra-Wideband, ICUWB 2007, Singapore, Sept. 2007.

Subject area Ultra Wideband, Body Area Networks, System Demonstrator
Type of work 90% Measurements and System Integration, 10% Theory
Students Stefan Müller, Marcel Favini
Supervisor Dr. Florian Trösch, Dr. Thomas Zasowski
Professor Prof. Dr. Armin Wittneben