碩士 / 國立臺灣海洋大學 / 電機工程學系 / 102 / In underwater voice communication systems, obstacles, such as very limited bandwidth of acoustic wave transmission, propagation delays of multipath and frequency selectivity of underwater channel, have made voice communication rather challengeable. In this thesis, an underwater voice communication system is proposed, which uses G.729 speech coder to reduce the voice size as well as the techniques of orthogonal frequency division multiplexing (OFDM) and pilot-based channel estimation and equalization to enhance the bandwidth efficiency of data transmission, reduce bit error rate, and increase the degrees of voice recognition and quality.
Simulation results show that the G.729 speech coder can enhance the degree of voice recognition. In addition, the techniques of orthogonal frequency division multiplexing (OFDM) and pilot-based channel estimation and equalization can reduce the bit error rate down to a tolerable region.
Keywords : voice communication, voice compression, underwater acoustic wave, orthogonal frequency division multiplexing, channel estimation, equalization, G.729 voice coding.
| Identifer | oai:union.ndltd.org:TW/102NTOU5442006 |
| Date | January 2014 |
| Creators | Lin, Ching-Chuan, 林清權 |
| Contributors | Hung, Hsien-Sen, 洪賢昇 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 44 |
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