Decentralized dynamic power control for cellular CDMA systems
نویسندگان
چکیده
The control of transmit power has been recognized as an essential requirement in the design of cellular code-division multiple-access (CDMA) systems. Indeed, power control allows for mobile users to share radio resources equitably and efficiently in a multicell environment. Much of the work on power control for CDMA systems found in the literature assumes a quasi-static channel model, i.e., the channel gains of the users are assumed to be constant over a sufficiently long period of time for the control algorithm to converge. In this paper, the design of dynamic power control algorithms for CDMA systems is considered without the quasi-static channel restriction. The design problem is posed as a tradeoff between the desire for users to maximize their individual quality of service and the need to minimize interference to other users. The dynamic nature of the wireless channel for mobile users is incorporated in the problem definition. Based on a cost minimization framework, an optimal multiuser solution is derived. The multiuser solution is shown to decouple, and effectively converge, to a single-user solution in the large system asymptote, where the number of users and the spreading factor both go to infinity with their ratio kept constant. In a numerical study, the performance of a simple threshold policy is shown to be near that of the optimal single-user policy. This offers support to the threshold decision rules that are employed in current cellular CDMA systems.
منابع مشابه
A New Class of Decentralized Interaction Estimators for Load Frequency Control in Multi-Area Power Systems
Load Frequency Control (LFC) has received considerable attention during last decades. This paper proposes a new method for designing decentralized interaction estimators for interconnected large-scale systems and utilizes it to multi-area power systems. For each local area, a local estimator is designed to estimate the interactions of this area using only the local output measurements. In fact,...
متن کاملNonlinear Multiuser Receiver for Optimized Chaos-Based DS-CDMA Systems
Chaos based communications have drawn increasing attention over the past years. Chaotic signals are derived from non-linear dynamic systems. They are aperiodic, broadband and deterministic signals that appear random in the time domain. Because of these properties, chaotic signals have been proposed to generate spreading sequences for wide-band secure communication recently. Like conventional DS...
متن کاملAdaptive Observer-Based Decentralized Scheme for Robust Nonlinear Power Flow Control Using HPFC
This paper investigates the robust decentralized nonlinear control of power flow in a power system using a new configuration of UPFC. This structure comprises two shunt converters and one series capacitor called as hybrid power flow controller (HPFC). A controller is designed via control Lyapunov function (CLF) and adaptive observer to surmount the problems of stability such as tracking desired...
متن کاملGame Theoretic Approach to Power Control in Cellular CDMA
In this paper, we present the power control problem in CDMA wireless data networks in the analytical setting of non-cooperative game theory. User satisfaction is represented as a net utility function, which is the difference of a strictly concave function, based on signal to interference ratio, and a cost term on user’s power. A detailed analysis for the existence and uniqueness of Nash equilib...
متن کاملOptimal Power Control for CDMA Systems in the Wideband Limit
Traditional methods for solving multiuser control problems in CDMA systems do not scale well as the number of users in the system increases. Indeed, the size and complexity of the control problem generally grows exponentially with the number of users. In order to find a tractable solution to these problems we develop a wideband limit approximation for dynamic programming problems in CDMA system...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- IEEE Trans. Wireless Communications
دوره 2 شماره
صفحات -
تاریخ انتشار 2003