Full-Duplex Cognitive Radio Networks

Abstract

With the proliferation of wireless services and the ever increasing data rate demands, spectrum resources have become more and more scarce. As a promising technique to increase the efficiency of spectrum utilization, Cognitive Radio (CR) has great potential to meet such a requirement by allowing unlicensed users (Secondary Users, SUs) to coexist in licensed bands allocated to licensed users (Primary Users, PUs). In conventional CR systems, the spectrum sensing is performed at the beginning of each time slot before the data transmission, which is also known as the “listen-before-talk” protocol. While this protocol has worked well in CR networks, two inherent problems still exist: 1) transmission time reduction due to sensing, and 2) sensing accuracy impairment due to data transmission.