Game Theoretic Approach to Joint CDMA Codeword and Power Adaptation

In this paper we present a distributed algorithm for joint codeword and power adaptation in the uplink of a Code Division Multiple Access (CDMA) system from the perspective of non-cooperative game theory. We define a new convex cost function based on which each user adjusts its codeword and power to meet a specified Quality of Service (QoS), and investigate existence and uniqueness of a Nash equilibrium point. Using the game-theoretic approach we also propose an algorithm for adjusting codewords and powers in a dynamic context, with variable QoS for active users. The proposed algorithm is illustrated with numerical examples obtained from simulations.