Noncooperative Power Control in CDMAWireless Networks

Contents 9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 9.2 Power Control in Wireless Cellular Networks and Game Theory. . . . . . . . . . . . . . . . . . . . . . . . 194 9.3 Power Control Games, Goals, and Utility Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196

9.3.1 Fixed SIR Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 9.3.2 Spectral Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 9.3.3 Energy Efficiency and Transmission Awareness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 9.3.4 Multiservice QoS-Aware Utilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202

9.4 Fixed SIR Power Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 9.4.1 Existence of Nash Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204

9.5 Spectral Efficacy via Power Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 9.5.1 Existence of Nash Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 9.5.2 Equilibrium’s Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 9.5.3 Convergence of Nash Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

9.5.3.1 Algorithm I (Spectral Efficiency Power Control Algorithm) . . . . . . . . . . . . 206 9.6 Energy-Efficient Power Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207

9.6.1 Existence of Nash Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 9.6.2 Equilibrium’s Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207

9.6.3 Convergence of Nash Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 9.6.3.1 Algorithm II (Energy-Efficient Power Control Algorithm) . . . . . . . . . . . . . 208

9.7 Energy-Efficient Power Control and Receiver Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 9.7.1 Existence of Nash Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 9.7.2 Equilibrium’s Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209

9.8 Energy-Efficient Power Control in Multicarrier CDMA Networks . . . . . . . . . . . . . . . . . . . . . . 209 9.8.1 Existence of Nash Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 9.8.2 Equilibrium’s Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 9.8.3 Convergence of Nash Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

9.8.3.1 Algorithm III (Best-Response Multicarrier Power Control Algorithm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

9.9 Energy-Efficient Power and Rate Control with Delay Prerequisites . . . . . . . . . . . . . . . . . . . . . . 211 9.10 Multiservices QoS-Aware Power Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213

9.10.1 Existence of Nash Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 9.10.2 Convergence of Nash Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

9.10.2.1 Algorithm IV (Multiservice Uplink Power Control Algorithm) . . . . . . . . 215 9.11 Power Control via Pricing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215

9.11.1 Existence of Nash Equilibrium and Pareto Optimality . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 9.11.2 Equilibrium’s Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 9.11.3 Convergence of Nash Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216

9.11.3.1 Algorithm V (Pricing Factor Algorithm (Network)) . . . . . . . . . . . . . . . . . . . . 217 9.12 Network-Centric Opposed to User-Centric Power Control and Base Station

Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 9.13 Joint Power and Signature Sequence Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 9.14 Concluding Remarks and Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222

With the growing demand for high data rates and support of multiple services with various quality of service (QoS) requirements, proficient power control mechanisms are essential toward efficient resource allocation and interference management in code division multiple access (CDMA) wireless networks. In this chapter, through a comprehensive analysis, concrete methodologies for treating various noncooperative power control games in CDMA wireless networks are presented, while the use and applicability of basic game theoretic tools in the design of power control approaches are illustrated. It is shown that game theory can be used as a unifying framework to study power control in CDMAwireless networks, as it provides a powerful theoretic tool that allowsmodeling and studying the interactions between self-interested users when competing for accessing scarce radio resources.

9.1 Introduction The inner characteristics of wireless communications in code division multiple access (CDMA) cellular systems, in terms of network’s scarce radio resources, mobile nodes’ physical limitations, and users’ time-varying channel conditions, have motivated the adoption of power control in both the uplink and downlink communication, toward proficient resource allocation and interference management. Power control aims at exploiting users’ channel quality rapid variations toward improving system’s and/or individual users’ performance, as well as achieving fairness and/or

meeting various services’ Quality of Service (QoS) criteria. This is realized by opportunistically allocating system’s resources in a time-slotted manner (i.e., transmission power and corresponding transmission rate) to the users with instantaneously “best channel” conditions, usually obtained through measurements and feedback.