Doppler effects on single-carrier signals operating in fading channels

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Authors
Smith, Jeffrey A.
Subjects
QAM
PSK
Fading Channels
Multipath Channels
Doppler Effect.
Advisors
Ha, Tri
Robertson, R. Clark
Date of Issue
2009-12
Date
Dec-09
Publisher
Monterey, California: Naval Postgraduate School
Language
Abstract
This thesis examines the performance of single-carrier systems in a fading channel environment. A transmission through a fading channel results in changes in phase and amplitude that degrade system performance. A pilot symbol in a single-carrier system can determine the channel characteristics, allowing reliable system performance. The differential decision feedback and double differential-decision feedback algorithms compensate for Doppler error by updating the channel phase estimation between each symbol. To determine the performance of single carrier systems in a fading environment, this thesis used MATLAB simulations. Each algorithm was tested for a variety of conditions to determine performance characteristics. Simulations for QPSK, 16-QAM and 64-QAM were implemented to test bandwidth efficient modulation using pilot symbols. Higher order QAM signals are less tolerant to phase errors since the signal constellation points are more densely located. These simulations showed that both algorithms can effectively compensate for Doppler errors in a fading channel with similar performance. In most situations the differential-decision feedback algorithm performed marginally better than the double-differential decision feedback algorithm.
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Thesis
Description
URI
https://hdl.handle.net/10945/48136
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Department
Electrical and Computer Engineering
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Approved for public release; distribution is unlimited.
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This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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