A Hybrid Cooperative Spectrum Sensing Scheme Based on Spatial-Temporal Correlation for CR-VANET
Xi Li, Tiecheng Song, Yueyue Zhang, Guojun Chen, Jing Hu · 2018
Cognitive radio enabled vehicular ad hoc networks (CR- VANETs) is one of the promising architecture in the future VANETs. In this paper, the joint spatial- temporal correlation is exploited to improve decision accuracy of cooperative spectrum sensing while reducing overhead introduced by cooperation in the CR-VANET. Firstly, a theoretical method is presented to analyze the impact of spatial-temporal correlation on cooperative sensing performance when using soft combining in the CR-VANET. Then, the expression of the optimal probability of detection with respect to spatial-temporal correlation is given for a target probability of false alarm by employing likelihood ratio test. Additionally, the user selection problem is formulated as an efficient double threshold optimization problem by considering both sensing accuracy and stability to achieve the optimal probability of detection. Finally, a hybrid cooperative spectrum sensing scheme based on spatial-temporal correlation is designed for the CR-VANET. Simulation results reveal that the proposed scheme could achieve significant sensing performance gain by selecting a subset of secondary users for combination, and could reduce user selection frequency by employing spatial- temporal diversity.