Hybrid accuracy-time trade-off solution for spectrum sensing in cognitive radio networks

Abstract

This paper explores how the vital function of spectrum sensing should be executed in cognitive radio networks. The cognitive receiver is required to be able to evaluate the spectral environment properly so that it may not create additional interference to the primary users. The sensing accuracy and time are conflicting parameters, therefore, a trade-off is necessary for an optimal efficiency. We propose a dual-approach solution. The decision about the spectrum occupancy is made using the measured signal-to-noise ratio (SNR) and the received signal levels as inputs in a fuzzy logic algorithm. The result is then compared with the one acquired using the statistical method. Finally, an optimal balance between the sensing time and accuracy is obtained for the current environmental conditions using the derived closed form expression. The algorithm has been implemented using the USRP platform and GNU Radio. The analysis of the results shows the efficiency of our proposal.