POWER CONTROL AND RESOURCE ALLOCATION FOR DELAY-CONSTRAINED COMMUNICATIONS By XIAOCHEN LI A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY

of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy POWER CONTROL AND RESOURCE ALLOCATION FOR DELAY-CONSTRAINED COMMUNICATIONS By Xiaochen Li August 2009 Chair: Dapeng Oliver Wu Major: Electrical and Computer Engineering Real-time applications such as streaming multimedia will be supported in the next generation wireless networks. Services required by these applications are different from file transfer services in that they expect low transmission delay, i.e., delay-constrained communications. Providing quality of service (QoS) guarantees to multimedia applications poses a significant challenge for the design of wireless networks. This dissertation focuses on the power and resource allocation schemes for delay-constrained communications, with statistical QoS requirements characterized by the triplet of data rate, delay bound, and delay bound violation probability. We study the optimal power control and resource allocation schemes to provide statistical QoS guarantees, which are more challenging than providing average delay guarantees, since statistical QoS imposes constraints on the distribution of transmission delay. In the first part of the dissertation, we study the throughput maximization problem subject to the delay bound violation probability and average power constraint, for a single-user, single-channel system. The buffer size is assumed to be infinite and the delay bound is relatively large. This problem is actually the effective capacity maximization problem, which is defined as the maximum data rate a system can sustain under the statistical QoS constraint, in large delay regime. We propose a simple cross-layer suboptimal power control scheme which significantly increases the effective capacity comparing to the optimal channel-gain-based power control scheme. We also