An Interference-Minimization Potential Game for OFDMA-Based Distributed Spectrum Sharing Systems

Wireless orthogonal frequency-division multiple-access (OFDMA) networks, where distributed users can access the spectrum dynamically, offer great flexibility and the potential for the efficient utilization of scarce spectrum resources. Despite that, managing such large-scale networks while maintaining fair and efficient spectrum usage poses a great challenge, mainly due to cochannel interference from the spatially reusable subcarrier. This paper considers the problem of interference minimization in such a scenario from a game-theoretical viewpoint. A general framework that defines the distributed OFDMA-based spectrum access problem is presented. Next, our game-theoretical analysis shows that the proposed interference-minimizing utility function exhibits the properties of a potential game. Given a deterministic number of subcarriers by each player, there exists a pure-strategy Nash equilibrium solution, and therefore, convergence can be guaranteed via sequential best-response dynamics. Our simulation results verify the analysis, and at the same time, the fairness and optimality of the solutions obtained through the proposed game are examined.