A Testbed Using USRP(TM) and LabView(R) for Dynamic Spectrum Access in Cognitive Radio Networks

Abstract

Dynamic spectrum access is regarded as a backbone for cognitive radio networks where unlicensed secondary users (SUs) access spectrum opportunistically which is licensed to licensed primary users (PUs). SUs are required to identify the idle bands and use them dynamically without creating any harmful interference to PUs. In dynamic spectrum access for peer-to-peer based communications, SU transmitter and its intended SU receiver must use common channel to communicate. Note that the fixed common control channel could not be viable in case of jamming attacks and wideband regime. Thus in this paper, we present a test bed using Universal Software Radio Peripheral (NI USRP) devices. We use Lab View® and MATLAB® scripting extensions to program NI USRP devices for peer-to-peer communications. Once SU transmitter and receiver pair knows idle channels, they use one of the best idle channels to communicate. We study sequential channel scanning and quorum based rendezvous methods without using any common control channels. These two schemes are compared in terms of their performance for finding suitable channel. Test bed is developed to test these schemes. Numerical results are presented obtained from test bed.