An Ergodic Algorithm for the Power-Control Games for CDMA Data Networks

摘要

In this paper, we consider power control for the uplink of a direct-sequence code-division multiple-access data network. In the uplink, the purpose of powercontrol is for each user to transmit enough power so that it can achieve the requiredquality of service without causing unnecessary interference to other users in thesystem. One method that has been very successful in solving this purpose for powercontrol is the game-theoretic approach. The problem for power control is modifiedas a Nash equilibrium problem in which each user can choose its transmit powerin order to maximize its own utility, and a Nash equilibrium is an ideal solutionof the power-control game. We present a noncooperative power-control game inwhich each user can choose the transmit power in a way that it gets the sufficientsignal-to-interference-plus-noise ratio and maximizes its own utility. To ensure theexistence of a solution, we also propose the variational inequality problem which isconnected with the proposed game. On a linear receiver, we deal with the matchedfilter receiver. Next we present a new ergodic algorithm for the proposed powercontrol because the existing iterative algorithms can not be applied effectively tothe proposed power control. We also present convergence analysis for the proposedalgorithm. In addition, applying the proposed algorithm to the proposed powercontrol, we provide numerical examples for the transmit power, the signal-to-interference-plus-noise ratio and so on. Numerical results for the proposed algorithmshall show that as compared with the existing power-control game and its method, allusers in the network can enjoy the sufficient signal-to-interference-plus-noise ratioand achieve the required quality of service.