| Summary: | 碩士 === 國立臺灣大學 === 工程科學及海洋工程學研究所 === 102 === The measurement error in realistic application for WSN exists due to hardware limitation and application conditions. On the other hand, how to prolong the life time of WSN is an important issue due to the limitation of battery capacity in sensors.
In previous research, both Bounded Error Data Compression (BEC) and Improved Bounded Error Data Compression (IBEC), used the bounded error in data compression under the condition of allowing data error to reduce the power consumption in WSN. Unlike BEC and IBEC, Bounded Error Huffman Coding (BEHC) proposed in this thesis uses the bounded error in Huffman coding. In data correlation compression, the compression ratio would be improved by that avoiding the excess bit composing the code and eliminating the defect of compressing the data under bounded error to longer code. In addition, after the research and observation of IBEC in this thesis, it shows that the data format and spatial correlation compression proposed by IBEC still has the defect. Therefore, New Improved Bounded Error Data Compression (NIBEC) which uses BEHC in off-line would be proposed to improve the data format and spatial correlation compression for higher effectiveness of compression.
In experiment result, four type raw data which have different correlation would be experimented and the results would compare with IBEC. The result shows that NIBEC improved 27%~47% compression ratio and reduced 25%~43% power consumption, and it proved that NIBEC improved the compression effectively.
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