Real-time spectrum sensor based on USRP

Cognitive radio (CR) technology promises to be one possible solution to address the lack of spectrum resources. The dynamic spectrum access approach is one of the key elements of CR, as it allows unlicensed users to access unused licensed frequency bands. In order to detect the presence of licensed users, one of the main tasks that a CR equipment has to perform is the spectrum sensing process. In this paper a real-time spectrum sensor implementation based on the Universal Software Radio Peripheral (USRP) platform is presented. Hardware and software details regarding the described prototype are given, together with aspects related to the optimal configuration of the used platform for such an application.