Implementation of Multi-Hop Cognitive Radio Testbed using Raspberry Pi and USRP

The increased usage of wireless communication has created a wireless frequency shortage problem. Cognitive Radio (CR) has attracted public attention, as one of the solutions that can resolve this issue. In this paper, the authors built an actual CR system testbed using the SDR (Software Defined Radio) platform, USRP (Universal Software Radio Peripheral) board, the SDR development toolkit, GNU Radio, and Raspberry Pi3, which is a single board computer. They configured Secondary User (SU)s with Raspberry Pi3 for straightforward and portable test environment. The authors' testbed performs spectrum sensing based on energy detection and determines whether the channel is occupied or not. Experimental results not only show performance but also provide their testbed that works well in multi-hop environments.