A Game-Theoretic Approach to Achieving Bilateral Privacy-Utility Tradeoff in Spectrum Sharing

In this paper, the problem of privacy-utility tradeoff in a database-driven spectrum sharing system is considered, where both primary users (PUs) and secondary users (SUs) may suffer from location privacy leakage. To protect the location information of both parties, a bilateral privacy preservation mechanism is introduced, in which the privacy-preserving levels are quantified. To tackle the dilemma that a higher privacy level leads to less available spectrum to share and thus reduces the profits of both parties, a game-theoretic approach based on the Stackelberg model is proposed to achieve the tradeoff between the privacy-preserving level and user utility. With the proposed approach, both PUs and SUs can maximize their utilities by adjusting their location privacy to desired levels. Simulation results demonstrate that the proposed approach can effectively increase the utilities for both PUs and SUs in comparison with the privacy preservation mechanism with a fixed privacy level.