Adaptive Transmission in Fading Environment

OF THE DISSERTATION Adaptive Transmission in Fading Environment by Lang Lin Dissertation Director: Professor Roy D. Yates and Professor Predrag Spasojević Adaptive transmission that varies the parameters at the transmitter using channel state information is a promising technique for improving bandwidth and/or power efficiency in time-varying wireless environments. To understand the full potential of adaptive transmission, the achievable throughput of adaptive transmission systems with practical constraints needs to be determined. In this thesis, we formulate and analyze power constrained average reliable throughput maximization with a finite number of code rates/power levels and with channel uncertainty. The focus is on communication over slow fading channels where the channel does not change over the duration of a codeword. Average reliable throughput is based on the concept of information outage, which can be related to the error performance of advanced coding designs. For an adaptive transmission system limited by encoding/decoding only with a finite choices of code rates, it is necessary to determine the finite set of code rates that enables the system to achieve maximum throughput. If the transmitted power also varies within a finite set of values, optimum designs are closely approximated by designs found by an iterative algorithm that maximizes the throughput by alternatively varying the sets of power levels and code rates. Numerical evaluations show that systems with ten