Experimental Studies on Energy / Eigenvalue based Spectrum Sensing Algorithms using USRP Devices in OFDM Systems

In this paper, we implement energy detection (ED) based spectrum sensing using NI USRP 2942R software defined radio platform. It is observed that in practical scenario ED scheme gives poor performance at low gain (G) values. To overcome the shortcomings of energy detection, we propose eigenvalue based detection of the primary user (PU) signal, where, the ratio of the maximum eigenvalue to the average eigenvalue is used to detect the PU signal. Further, the experimental studies show that proposed technique gives optimum probability of detection. It has been observed that the proposed technique outperforms the ED based detection even if the Tx-Rx separation increases.