Cooperative Spectrum Sensing and Fusion Based on Tangle Networks

Cooperative spectrum sensing (CSS) is a promising solution to improve the spectrum sensing performance. However, some cooperative secondary users (SUs) may intentionally send wrong spectrum sensing results for the benefit of themselves, which will bring security problems to the CSS-enabled systems. Besides, the behavior of the primary user (PU) may change dynamically when SUs sense the spectrum, which affects the accuracy of CSS. In this paper, a CSS architecture based on the Tangle blockchain is proposed, where massive mobile devices (MDs) act as spectrum sensing nodes and blockchain nodes. A novel dynamic spectrum sensing algorithm is proposed based on the mean-field game. A two-step spectrum sensing fusion mechanism based on the age of information (AoI) and cumulative weight (CW) of transactions is proposed to address the impact of perceptual data differences on the overall decision. The simulation results show that, compared with the traditional fixed spectrum sensing strategy, the MDs’ weighted sensing utility in the proposed dynamic spectrum sensing scheme is improved by 10% on average. Moreover, compared to the traditional maximal ratio combining fusion mechanism, the detection probability of the proposed two-step spectrum sensing fusion mechanism is maximally increased by 30.23%, and the false alarm probability is minimally reduced by 9.92%.