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Please use this identifier to cite or link to this item: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/18822

Title: 基於時空編碼之正交分頻多工水下聲音傳輸技術設計
STBC OFDM-Based Transmission Scheme for Underwater Acoustic Audio
Authors: Wei-Hua Chen
陳偉華
Contributors: NTOU:Department of Electrical Engineering
國立臺灣海洋大學:電機工程學系
Keywords: 水下分頻多工技術;時空編碼;聲音壓縮技術G.729;混沌加密
OFDM;STBC;G.729 audio signal;chaos-based encryption
Date: 2010
Issue Date: 2011-07-04T01:04:10Z
Abstract: 正交分頻多工技術應用在現今的無線傳輸技術中最為廣泛。為了能應用於水下聲學通道,在此篇論文中,我們結合正交分頻多工技術、功率配置機制、適應性調變技術、時空編碼 (Space Time Block Coding,STBC) 和不同程度通道編碼機制 (unequal error protection technique) 來建構一個完整的水下聲音無線傳輸系統。除此之外,為了降低無線傳輸資料量的負擔,我們採用G.729的聲音壓縮技術,對水下聲音資料進行壓縮。針對水下聲音資料的保密性及安全性,也透過混沌加密機制來實現。藉由程式模擬水下聲音在水下通道的傳輸,比較直接映射與時空編碼在水下無線傳輸的環境中,哪一種技術的抗干擾性較好及較省電,同時我們透過平均均方誤差 (Mean Square Error, MSE) 來了解聲音在時空編碼過後的失真度。另外為了驗證加密機制的安全性及穩定性,我們也透過不同的解密手法來還原聲音波形,並與原始聲音波形來比較MSE值。模擬結果與我們的假設相符。
Now days, the orthogonal frequency division multiplexing (OFDM) technology is widely applied to wireless transmission technology. In this thesis, we propose a combination of orthogonal frequency division multiplexing (OFDM), power allocation mechanism, adaptive modulation, Space-Time Block Coding (STBC) and unequal error protection technique to construct a complete scheme of underwater acoustic audio transmission for an underwater acoustic channel. In addition, we have to reduce the amount of data in order to achieve audio signal transmission, so we introduced a G.729 voice compression technology to the proposed system. We have also discussed a chaos-based encryption mechanism in the proposed underwater acoustic audio transmission system. Simulation results show that the proposed system is a good transmission platform for an underwater acoustic audio signal.
URI: http://ethesys.lib.ntou.edu.tw/cdrfb3/record/#G0T97430015
http://ntour.ntou.edu.tw/ir/handle/987654321/18822
Appears in Collections:[電機工程學系] 博碩士論文

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