Hybrid spectrum sensing experimental analysis using GNU radio and USRP for cognitive radio

The dynamic spectrum access is a concept opposite to static frequency spectrum assignment and one of the key elements of cognitive radio (CR). It allows secondary users to access unused licensed frequency bands. In order to detect the presence of primary users, one of the fundamental tasks that a CR equipment has to perform is spectrum sensing process. In this paper, a hybrid spectrum sensing architecture is proposed, which consists of the concatenation of a sequential energy detection (SED) and a cyclostationary-based (CB) detector. The former sensing method is performed to reduce spectrum sensing time, when the SNR is very high (resp. very low), while the latter sensing detector is performed whenever the SED does not guarantee the required quality of detection (i.e. moderate SNR regime). The efficiency of the proposed solution has been verified experimentally using USRP N210 boards under GNURadio environment.