Comparison of Nonquiet Spectrum Sensing in Filter Bank Multicarrier and OFDM Based Cognitive Radio Systems

Filter bank multicarrier (FBMC) and orthogonal frequency division multiplexing (OFDM) have been recognized as two physical layer (PHY) candidates for Cognitive Radio (CR) systems. Spectrum sensing plays an important role in a CR in order to detect spectrum opportunities. It is usually more desirable to perform spectrum sensing without additional hardware. In this paper, a comparison between performance of filter bank-based (FB-based) and fast Fourier transform-based (DFT-based) energy detectors (EDs) is presented. These methods are used in FBMC and OFDM PHYs with a slight modification to the hardware, respectively. For this comparison the area under the receiver operating characteristic (ROC) curve namely AUC is considered as a criterion. Moreover, the performance comparison is conducted under the condition that secondary users (SUs) continue their transmission even in the sensing period. As a result, the SU which is performing primary user (PU) detection receives the interference from SUs. This is called nonquiet sensing. The results indicate that although DFT-based ED is less complex, FB-based ED's performance is much better than DFT-based ED in heavy interference environment.