A game-theoretic approach to efficient power control in CDMA data networks

Game theory is a branch of mathematics and is a powerful tool for analyzing resource conflicts. In wireless communication systems, power and bandwidth (spectrum) are two fundamental and conflicting resources. Efficient use of these resources in the operation of wireless communication systems is challenging. In this paper, the application of game theory for studying uplink power control in code-division multiple-access (CDMA) networks is proposed. Power control problem is modeled as a N-person non-cooperative game in which each mobile user tries to maximize its own utility without any deal among the users. A utility function is defined for each user, which represents the user's choice with respect to the carrier-to-interference ratio (CIR) and the transmitter power. Two main assumptions are made about the utility function in this work. Under the two assumptions, it is shown that there exists an optimum operating point referred to as a “Nash equilibrium” that is unique. One special condition is studied by defining the utility as a linear function. This basic model covers many of the studied power control problems.