Cognitive Radio Research - Project Overview

Introduction

The Cognitive Radio project aims to develop radios that can sense the existing spectrum and identify and use free frequency bands. The motivation for these radios comes from the apparent scarcity of spectrum as indicated by the multiple allocation of most bands by the FCC. On the other hand, studies by the FCC show that 70% of the allocated spectrum is not utilized. This discrepancy between allocation and use provides the motivation for opportunistic use of the spectrum. 

As a part of the Cognitive Radio project we aim to address the policy and technology issues that are needed for the deployment of intelligent radios.  

Fig. 1(a) shows the spectrum allocation chart for the United States which resembles a patch work quilt. It is worthy to note that frequencies between 1 and 5GHz have been allocated multiple times. Compare this with the sensing results shown in Fig. 1(b). These measurements were performed at the BWRC over a period of 10 seconds. The PCS bands see  significant  energy while the ISM bands see intermittent energy (due to WiFi). 

  Fig 1(a): Spectrum Allocation by the FCC.

Fig 1(b): Spectrum use measured at the BWRC.