碩士 / 國立海洋大學 / 電機工程學系 / 88 / Since the energy of high frequency radio wave decays rapidly in the water, the low frequency
acoustic wave becomes the main choice for underwater communication. However the underwater acoustic
channel is characterized as a time-varying and multipath fading channel, the decay of energy,
the interference from multipath, and the spreading of phase and frequency will influence the
quality of underwater communication. Therefore, it''s an important issue to choose a suitable
communication technique to overcome the aforementioned problems.
In this thesis, a prototype underwater acoustic voice modem for audio signals transmission is
implemented. We use the equalization technique for eliminating the effect of multipath, and
use modulation techniques such as BPSK, QPSK, DQPSK to reduce the distortion of the signal.
We use the DSP TMS320C31 as the kernel and some external hardware to
implement the system. Through actual experiments in a lab water tank, we verify the
validity of the proposed underwater acoustic voice modem system.
| Identifer | oai:union.ndltd.org:TW/088NTOU0442062 |
| Date | January 2000 |
| Creators | 李錫龍 |
| Contributors | 曾敬翔 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 53 |
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