Thesis
Shallow under water communication with passive phase conjugation and iterative demodulation and decoding
Washington State University
Master of Science (MS), Washington State University
2008
Handle:
https://hdl.handle.net/2376/100884
Abstract
In this thesis we propose a system of passive phase conjugation with iterative demodulation and decoding to increase information throughput in the shallow underwater acoustic channel. The system incorporates passive phase conjugation to mitigate inter-symbol interference caused by the severe multipath environment encountered in the shallow water acoustic channel and a soft-input, soft-output demodulation and a soft-input, soft-output channel decoder in an iterative ‘turbo’ structure to improve the bit error rate performance at higher symbol rates. The system incorporates a linear estimator to estimate slowly varying phase from the channel and to account for Doppler shifts due to source or receiver motion. The system was successfully simulated and achieved a 10−3 bit error rate at signal to noise ratios as low as 3.2 dB with random slowly varying phase changes. The system was tested at Lake Pend Orielle in Idaho over a distance of 1.78 km in shallow water with bit error rates below 10−5 at 2,500 information symbols per second using a 25 kHz carrier.
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Details
- Title
- Shallow under water communication with passive phase conjugation and iterative demodulation and decoding
- Creators
- Christopher Corson Keeser
- Contributors
- Benjamin Joseph Belzer (Degree Supervisor)Thomas Fischer (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525148901842
- Language
- English
- Resource Type
- Thesis