A non-cooperative power control game for secondary spectrum sharing

Limited spectrum resources, inefficient spectrum usage and increasing wireless communication necessitates a paradigm shift from the current fixed spectrum management policy to a more flexible one. With the Federal Communications Commission's (FCC) spectrum policy reform, secondary spectrum sharing has become a viable and promising option. In this paper, we study power control for spectrum sharing among secondary users with interference temperature limit (ITL) constraints at measurement points. Each secondary user will adjust its own transmission power to make sure the overall interference at the measurement points does not exceed the required ITL. Under the assumption that each secondary user is selfish and rational while there is only limited coordination between primary users and secondary users, we study the distributed power control scheme for secondary users. In our proposed system model, secondary users generating the highest interference at a measurement point will back off their transmissions if the ITL is exceeded. A non-cooperative power control game among secondary users is proposed to maximize each user's utility. We identify the Nash equilibrium of the proposed game and analyze its property. Simulations are conducted to demonstrate that the proposed solution can achieve a satisfactory performance in terms of the total transmitting rate of all the secondary users.