Spectrum Sensing, Access and Coexistence Testbed for Cognitive Radio using USRP

The idea of cognitive radio has created a great interest in academic and industrial research recently. As a result, there are a large number of proposals for physical and network layer functionalities. In this paper, we demonstrate an experimental platform with the USRP board developed by Ettus Research that can facilitate the development of PHY and MAC layers functionality. Some key results from this experience so far are presented, including an over-the-air interoperability analysis of two different SDR (software defined radio) architectures in the same frequency band, the effect of dynamic spectrum access on legacy system and analysis of actual co-existence experiences involving primary users and secondary opportunistic spectrum users. In particular, we focus our attention on spectrum sensing and spectrum coexistence as an example that incorporates both digital signal processing and networking techniques to show how this platform could be used to conduct comprehensive research in cognitive radio.