臺灣博碩士論文加值系統

近年來，結合分散式偵測及錯誤更正碼的技術被提出來並且應用在無線感測器網路上，使得系統能具備容忍錯誤的能力。每一個感測器根據自己的觀察值及區域決策法則做出決策。接著這個區域決策將被傳送到資料融合中心並做出全域性決策。但是當觀察值不夠可靠或者通道雜訊干擾較嚴重時，這個方法的錯誤率就會上升。因此本篇論文提出適應性重新偵測及重新傳送來解決這個問題。重新偵測演算法是在每一個感測器上設定一個重測區間。當感測器的觀察值沒有落在這個區間內，則感測器將做出決策。反之，感測器將重新偵測一次。在重新傳送演算法裡，資料融合中心會將所收到區域決策換算成可靠度並做出全域決策。但是當全域決策不夠可靠時，資料融合中心將會要求資料中可靠度最小的感測器重新傳送一次區域決策。由模擬的結果得知，利用了重新偵測及重新傳送演算法能夠有效的降低錯誤率。

An approach combining distributed detection with error-correcting codes has recently been proposed to design a fault-tolerant classification system in wireless sensor networks. Each sensor makes a local decision according to its detection result and local decision rules. The local decision then is transmitted to a fusion center for making a final decision. The misclassification probability using this approach is high when the detection result is not reliable or the transmission channel is highly noisy. This thesis proposes adaptive retransmission and redetection schemes to resolve this problem. An unreliable range is set for each sensor in the redetection scheme. If the detection result of the sensor is not located in the unreliable range, the sensor makes a local decision. Otherwise, the sensor has to make another detection. In the retransmission scheme, the fusion center calculates reliability of each received detection result while making the final decision. When the final decision is not reliable, the sensor which has sent the received result with the lowest reliability will be asked to retransmit its detection result by the fusion center. Simulation results show that the misclassification probability can be effectively reduced through the redetection and the retransmission.

第一章 緒論 8
1.1 無線感測器網路簡介 8
1.2 無線感測器的應用 8
1.3 無線感測器的限制 9
1.4 分散式處理 11
1.5 論文架構 13
第二章 使用錯誤更正碼的分散式分類法 15
2.1 文獻綜覽 15
2.2 DCFECC簡介 17
2.3 最佳區域決策法則 18
2.4 DCFECC-SD 的全域決策法則 21
2.5 最佳編碼矩陣 22
第三章 重新偵測與重新傳送演算法 28
3.1 問題描述 28
3.2 重新傳送演算法 30
3.3 重新偵測演算法 33
第四章 模擬與討論 38
4.1 重新偵測演法的模擬與分析 38
4.2 重新傳送演法的模擬與分析 42
4.3 結合重新偵測及重新傳送演算法的模擬 50
第五章 結論與未來展望 57
參考文獻 58

[1]I. F. Akyildiz,W. Su, Y. Sankarasubramaniam, and E. Cayirci, “A survey on sensor networks,” IEEE Commun. Mag., vol. 40, no. 8, pp. 102–114, Aug. 2002.
[2]N. Noury, T. Herve, V. Rialle, G. Virone, E. Mercier, G. Morey, A. Moro, and T. Porcheron, “Monitoring behavior in home using a smart fall sensor,” in Proc. First Annu. Int. IEEE-EMBS Conf. Micortechnologies in Medicine and Biology Lyon, France, 2000, pp. 607-610.
[3]E. Shih et al., “Physical layer driven protocol and algorithm design for energy-efficient wireless sensor networks,” in Proc. of the Seventh Annual ACM/IEEE International Conference on Mobile Computing and Networking, pp. 272–286, July 2001.
[4]I. F. Akyildiz,W. Su, Y. Sankarasubramaniam, and E. Cayirci, “Wireless sensor networks: A survey,” IEEE Computer, vol. 38, no. 4, pp. 393–422, Mar. 2002.
[5]D. Culler, D. Estrin, and M. Srivastava, “Guest editors’ introduction: Overview of sensor networks,” IEEE Computer, vol. 37, no. 8, pp. 41–49, Aug 2004.
[6]M. Tubaishat and S. Madria, “Sensor networks: An overview,” IEEE Potentials, vol. 22, no. 2, pp. 20-23, Apr./May 2003.
[7]P. H. Chou, Chulsung Park, “Energy-efficient platform designs for real-world wireless sensing applications,” in Proc. ICCAD 2005, IEEE/ACM Intl. Conf. 6-10 Nov. 2005 Page(s):913 – 920
[8]T. -Y. Wang, Y. S. Han, P. K. Varshney, and P.-N. Chen, “Distributed fault-tolerant classification in wireless sensor networks,” IEEE J. Selected Areas Comm., vol. 23, no. 4, pp. 724-734, Apr. 2005.
[9]T. -Y. Wang, Y. S. Han, B. Chen, and P. K. Varshney, “A combined decision fusion and channel coding scheme for fault-tolerant classification in wireless sensor networks,” IEEE Trans. Wireless Commun.
[10]G. G. L. Meyer, H. L. Weinert, “On the design of fault-tolerant signal detectors,” IEEE Trans. Acoust., Speech, Signal Process., vol. ASSP-34, no. 4, pp. 973–978, Aug. 1986.
[11]R. Viswanathan, P. K. Varshney, “Distributed detection with multiple sensors Part I: Fundamentals,” Proc. IEEE, vol. 85, pp. 54-63, Jan. 1997.
[12] P. K. Varshney, Distributed Detection and Data Fusion, New York. NY: Springer, 1997.
[13]T. Clouqueur, K.K. Saluja and P. Ramanathan, “Fault tolerance in collaborative sensor networks for target detection,” IEEE Trans. Computers, vol. 53, pp. 320-333, Mar. 2004.
[14]S. Lin and D. J. Costello, Error Control Coding, Second Edition, Prentice-Hall, Inc., Upper Saddle River, NJ, 2004
[15]A. E. Gamal, L. A. Hemachandra, I. Shperling, and V. K. Wei, “Using simulated annealing to design good codes,” IEEE Trans. Inf. Theory, vol. IT-33, no. 1, pp. 116–123, Jan. 1987.
[16]H.-T. Pai, J.-T. Sung, and Y. S. Han, “A simple two-dimensional coded detection scheme in wireless sensor networks,” in Proc. ICPADS 2005, Fukuoka, Japan, July 2005, pp. 383-387.
[17] D. G. Brennan, “Linear diversity combining techniques,” Proc. IEEE, vol. 91, no. 2, pp. 331-356, Feb. 2003.
[18]A. Leon-Garcia. Probability and Random Processes for Electrical Engineering, Second Edition. Addison Wesley, 1994.