Date of Award

5-2008

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Legacy Department

Electrical Engineering

Advisor

Pursley, Michael B

Committee Member

Brawley , Joel V

Committee Member

Noneaker , Daniel L

Committee Member

Russell , Harlan B

Abstract

Protocols for modulation selection, initial transmitter power adjustment, modulation and coding adaptation, and transmitter power adaptation are presented. Most adaptive protocols in the literature are for full-duplex communication and they require channel estimation (e.g., using training symbols); however, our protocols are for half-duplex packet radios and they do not require estimation of the channel for adaptation. Instead, our protocols are driven by statistics that can be derived from the receiver's demodulator or decoder. We present the protocols in the context of their application to dynamic spectrum access networks. Our protocols are designed for adaptive radios, of which software-defined radios and cognitive radios are special cases. We describe and evaluate techniques that enable cognitive radios to adjust the decision thresholds of an adaptive transmission protocol based on past results. Finally, we describe statistics from our adaptive transmission protocol that can be used to provide information to higher-layer protocols and cognitive processes.

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