Game theoretic approach to quality of service and resource management in wireless systems

Next generation wireless systems will be required to support heterogeneous services with different transmission rates that include real time multimedia transmissions, as well as non-real time data transmissions. In order to provide flexible transmission rates to each terminal, efficient use of system resources in next generation systems will require transmission rate control in addition to power control. In this study the problem of joint rate and power control is approached from the perspective of noncooperative game theory. The motivation for a game theoretic approach to the joint rate and power control is twofold. First, the computational resources are distributed and all the users have different requirements. Second, the users are likely to behave in a selfish manner which is difficult to characterize using conventional techniques and models. Game theory provides a suitable framework for characterizing such settings.; Our first goal is to formulate the joint problem of rate and power control in the game theoretic framework, where each players preferences are given by the utility function. Utility, in the case of wireless data systems is can be thought of as the number of information bits received successfully per Joule of energy expended. We formulate the utility of a data user in terms of intrinsic properties of the channel, which depends on the signal to interference ratio (SIR), and can be adjusted to provide the desired Quality of Service (QoS) requirement. We formulate the joint rate and power control as a noncooperative game and develop a distributed algorithm which determines the optimal rate of transmission and allocates the power required to transmit in the same step.; A detailed analysis of the existence and uniqueness of Nash equilibrium for the non-cooperative joint transmission rate and power control game is presented. In noncooperative rate and power control, each terminal maximizes its corresponding utility by adjusting its rate and power ignoring potential harmful effects (amount of interference) it has on other users in the system. The concept of pricing is used to control these effects in the noncooperative environments. Next, we introduce the concept of pricing and require the users to maximize net utilities, that is utility minus pricing. We observe that there are two resources, transmission rate and transmit power. We show the improvements in the utilities of users by using the usage based pricing scheme, when the price is proportional to transmission rate and when the price is proportional to the transmit power. We show that there exists an unique Nash equilibrium in the non-cooperative joint rate and power control games with pricing, which is superior, and present an algorithm which reaches this equilibrium. Wireless Communication is requiring additional spectrum to satisfy the demand for various applications and data rates. The licensed spectrum is limited and the new spectrum will not be available soon, as regulatory changes of the regulatory status from licensed to unlicensed bands are complicated and usually take a long time. Today, many frequency bands are often unused, for instance frequencies licensed for TV/radio broadcasts or public safety services. Further more, future radio systems are required to support QoS in a shared spectrum i.e. in the presence of other radio systems. Flexible and dynamic spectrum usage requires an intelligent medium access, especially in the face of QoS support. They identify radio spectrum when it is unused by the incumbent radio system and use this spectrum in an intelligent way based on spectrum observation.; Second aim of this work is to develop a distributed algorithm for spectrum allocation in cognitive radios based on a non-cooperative game theoretic approach as the users when sharing the open spectrum act in a selfish manner and a non-cooperative game theoretic framework gives an outcome which is an equilibrium that is best for all users. We introduce the sy...