Cooperative spectrum sensing can effectively protect licensed users from harmful interference and satisfy the quality-of-service requirements of secondary users (SUs) in cognitive radio networks. In this paper, a novel joint quantization and confidence-based generalized (JQCG) combining scheme is proposed. A centralized approach is considered for cooperative spectrum sensing with SUs using the energy detector as a local spectrum sensing scheme. The confidence level is calculated using a fuzzy logic membership function for each cooperative SU. In the proposed JQCG combining scheme, each cooperative SU transmits multiple bits instead of transmitting one bit (hard combining) or the complete test statistic (soft combining) to report local sensing results to the fusion center (FC). We also derive optimal weights (in Neyman–Pearson sense) for each quantized level at the FC to maximize the probability of detection for a given false alarm probability. The proposed JQCG combining scheme is validated by extensive simulation results showing that it has a comparable performance to the soft combining scheme with less overhead. Extensive computer simulations show that the JQCG combining scheme significantly outperforms the hard combining and existing quantized schemes for cooperative spectrum sensing.

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Journal IEEE Systems Journal
Ejaz, W. (Waleed), Hattab, G. (Ghaith), Attia, T. (Takwa), Ibnkahla, M, Abdelkefi, F. (Fatma), & Siala, M. (Mohamed). (2016). Joint Quantization and Confidence-Based Generalized Combining Scheme for Cooperative Spectrum Sensing. IEEE Systems Journal. doi:10.1109/JSYST.2016.2615019