Ad-Rem – Ad-Hoc Dynamic Radio-Spectrum Exploitation via Multi-Phase Radio

Description of research

Spectrum is the lifeblood of RF Communications. To avoid interference, radio communication is subject to regulations, which assign dedicated parts of the radio frequency spectrum to dedicated services, such as FM-radio, TV broadcasts, GSM, etc. Measurements all over the world, such as the one made in Bern by Swisscom (figure 1), show that large parts of the spectrum are not or rarely used, while other parts are overcrowded.

To better exploit the scarce available spectrum, new radio devices could monitor the locally available spectrum, and use unused or "white space", but "step aside" if traditional radio services enter the picture. This requires a smart agile radio transceiver, referred to as a Cognitive Radio (CR). The term 'cognitive' stands for awareness of the surrounding environment; in our project we limit this awareness to availability of the spectrum.

Traditional radio transreceiver circuits are narrowband in order to be robust against interfering signals in the neighboring bands of the spectrum. Because the frequency band is fixed, external (expensive) RF-filters can be used for filtering. In CR, the frequency bands are not fixed and may even vary during a single session. Using those external filters for each band is a bulky and costly solution. Building flexible filters with very high out of band interference rejection is not yet possible in our days. Therefore, building broadband receiver with relaxed RF-Filter requirements is highly desired. Broadband receivers means no any rejection against interferers (Interferers = distortions), which makes the linearity an important and critical specification in CR Front-End.

The goal of the project is to design a broadband fully functional CR receiver chip in CMOS with very high linearity and adequate noise figure.

Advisor(s)

Dr. ing. E.A.M. Klumperink

Prof.dr.ir. B. Nauta

Duration

1 May 2008 to 1 May 2012

Project

ADREM – Ad-Hoc Dynamic Radio-Spectrum Exploitation via Multi-Phase Radio

Funding institution

Technologiestichting STW

Strategic Research Orientation

Wireless and Sensor Systems

Links to relevant web pages:

http://icd.ewi.utwente.nl/persons/?id=259

Pictures