T22: Signal Processing Techniques for Spectrum Sensing & Communication Presenter: Behrouz Farhang-Boroujeny, University of Utah

Abstract

As the vast majority of the available spectral resources have already been licensed, it appears that there is little or no room to add any new services, unless some of the existing licenses are discontinued. On the other hand, studies have shown that vast portions of the licensed spectra are rarely used. This has initiated the idea of cognitive radio (CR), where secondary (i.e., unlicensed) users are allowed to transmit and receive data over portions of spectra when primary (i.e., licensed) users are inactive. This should be done in a way that the secondary users (SUs) are invisible to the primary users (PUs). The FCC Spectrum Policy task force has already set the rules for the operation of CR networks. Standard working groups, e.g., IEEE 802.22, have also been formed and are currently working on relevant documents or have finalized the standards. This tutorial addresses a range of signal processing tools that are available for both spectrum sensing and communications, in CR settings. The emphasis will be on OFDM and multicarrier filter bank techniques.

Biographies

Dr. Behrouz Farhang-Boroujeny received the Ph.D. degree from Imperial College, University of London, UK, in 1981. Dr. Farhang is an expert in the general area of signal processing. He has over 25 years of post PhD experience in teaching and doing research in this field. In the past he has worked in the diverse fields of audio signal processing, magnetic and optical recording channels, CDMA and multicarrier communication systems, MIMO communications, and more recently he has been involved with research related to cognitive radio systems. In this area, his team has studied possible applications of various multicarrier techniques, including the conventional OFDM and filter bank based schemes, in cognitive radio systems. Their study also includes cross-layer issues in CR networks. Dr. Farhang‚s research in the area of cognitive radio is well received in the industry and among academic community. A team of his students won the best paper award of the 2007 Software Defined Radio (SDR) Conference. SDR conference is managed by the SDR forum whose mission is stated as „a non-profit international industry association dedicated to supporting the development and deployment of software defined and cognitive radio technologies that enable flexible and adaptable architectures in advanced wireless systems.‰

Dr. Farhang has also published papers on the topic of cognitive radios in conferences, and has the following two accepted journal papers: [1] B. Farhang-Boroujeny, „Filter bank spectrum sensing for cognitive radios,‰ IEEE Trans. On Signal Processing, Accepted. [2] B. Farhang-Boroujeny and R. Kempter, „Multicarrier communication techniques for spectrum sensing and communication in cognitive radios,‰ IEEE Commun. Magazine, Accepted. He also has been invited to write a book chapter in „Handbook on Sensor and Array Processing‰ (Editors: Simon Haykin and Ray Liu) on the subject of „Spectral Estimation in Cognitive Radios.