Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)

Legacy Department

Electrical Engineering

Committee Chair/Advisor

Dr. Michael B. Pursley

Committee Member

Dr. Daniel L. Noneaker

Committee Member

Dr. Harlan B. Russell

Committee Member

Dr. Taufiquar Khan


We present low-complexity adaptive protocols for both unicast and multicast transmission in wireless communication systems that employ higher layer fountain codes. Our adaptive protocols respond to variations in channel conditions by adapting the modulation and channel coding of transmitted packets, and they provide efficient communication over wireless channels that experience fading, shadowing, and other time-varying propagation losses. The operation of our protocols is governed by simple receiver statistics that can be obtained during the demodulation of received packets. We present three adaptive protocols for fountain-coded unicast transmission, and compare the throughput performance of our protocols with that of fixed-rate systems, as well as hypothetical ideal protocols that are given perfect channel state information and use ideal fountain codes. We also present two adaptive protocols for fountain-coded multicast transmission. Our adaptive multicast transmission protocols operate with limited feedback from the destinations and provide scheduling to avoid collisions among the feedback messages. We compare the performance of our multicast protocols to systems with fixed modulation and coding, as well as hypothetical protocols that are given perfect channel state information. We demonstrate that our practical adaptive protocols for fountain-coded unicast and multicast transmission outperform fixed-rate coding schemes and provide throughput that is nearly as high as that achieved by hypothetical protocols that are given perfect channel state information.



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