碩士 / 國立海洋大學 / 電機工程學系 / 85 / The ocean is a time-varing and reverberant environment. The
energy of radio wavewill be attenuated rapidly with the
increasing of frequency. Thus, the acoustic wave is an
appropriate medium for underwater data transmission. The
amplitude variations, termed singal fading, are due to time-
variant characteristicsof the channel.The amplitude of the
multipath fading signal has the statistical propertiesof
Rayleigh distribution. The spread spectrum techniques is
frequently used in digital communications. It has the advantages
of antijamming, antiinterference, and antimultipath. In this
thesis,the SPW(Signal Processing Worksystem) is applied to
simulate QPSK(quadriphase-shift keying) direct secquence spread
spectrum system in Rayleigh fading channe with various Doppler
effects.The discrete signal processor is also used to modulate,
transmit, recive, and demodulate signal for implementing the
processed transmission method.The transmission experiments are
conducted between two personal computers.When the signal is
transmitted through the cable, the received waveform isperfect,
and the transmission has no error. However, due to the
frequencylimitation of transducers, the transmission through air
has some tolerableerrors.
| Identifer | oai:union.ndltd.org:TW/085NTOU0442032 |
| Date | January 1997 |
| Creators | Shi, Wei, 徐偉 |
| Contributors | Lu Fu-Hseng, 呂福生 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 86 |
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