Multiobjective distributed power control algorithm for CDMA wireless communication systems

Although power control has been explored since the early 1990s, there still remains the need for further research. Most of the algorithms so far consider either the problem of minimizing the sum of transmitted power under quality of service (QoS) constraints given in terms of minimum signal-to-interference-plusnoise ratio (SINR) in a static channel or the problem of mitigating fast fading in a single dynamic link. In this paper, we suggest a new approach to the power control by treating the QoS requirement as another objective for the power control and a fully distributed method for solving the multiobjective power optimization problem. The obtained solution is parameterized so that a tradeoff can be made between power consumption and QoS. In the limit case, when only QoS is weighted, the algorithm reduces to the well-known distributed power control algorithm (IEEE Trans. Commun., vol. 42, no. 2/3/4, pt. 1, Feb./Mar./Apr. 1994). In the other limit, the algorithm reduces to transmission with fixed minimum power. The convergence properties of the proposed algorithm are studied both theoretically and with numerical simulations. Although we only consider SINR and power sum, our algorithm could be easily modified to take other objectives, such as throughput, into account.