A Hybrid Noncooperative Game Model for Wireless Communications

Abstract

We investigate a hybrid noncooperative game motivated by the practical problem of joint power control and base station (BS) assignment in code division multiple access (CDMA) wireless data networks. We model the integrated power control and BS assignment problem such that each mobile user’s action space includes not only the transmission power level but also the respective BS choice. Users are associated with specific cost functions consisting of a logarithmic user preference function in terms of service levels and convex pricing functions to enhance the overall system performance by limiting interference and preserving battery energy. We study the existence and uniqueness properties of pure strategy Nash equilibrium solutions of the hybrid game, which constitute the operating points for the underlying wireless network. Since this task cannot be accomplished analytically even in the simplest cases due to the nonlinear and complex nature of the cost and reaction functions of mobiles, we conduct the analysis numerically using grid methods and randomized algorithms. Finally, we simulate a dynamic BS assignment and power update scheme, and compare it with “classical” noncooperative power control algorithms in terms of aggregate signal-to-interference ratio levels obtained by users.