任意规模大型无线传感网络中的分布式监测和数据融合.doc

任意规模大型无线传感网络中的分布式监测和数据融合（译文） Ruixin Niu, Pramod K.Varshney （Syracuse大学电子工程与计算机科学系，335 Link Hall, Syracuse, NY 13244-1240, USA） 摘要：针对一个传感器个数随机的无线传感网络，本文提出一种决策融合法则。本法则把来自本地传感器的监测总量作为假设检验的统计量，并假设信号能量衰减是到对象距离的函数，同时传感器个数服从泊松分布，在关键域（ROI）内的传感器位置服从均匀分布。随后本文将给出系统级监测性能的分析和仿真结果。只要传感器的平均数量达到足够的大，本融合法则就能具备很好的系统级监测性能，甚至极低信噪比（SNR）的情况下。对于已研究的各种系统参数，本法则等同于需要更多先验信息的最佳融合法则。最后，本文针对不同的系统参数，研究了如何通过最大化偏转系数的方法，来定量地确定本地传感器级的最佳阈值。 关键词：无线传感网络，分布式监测，决策融合，偏转系数 Distributed Detection and Fusion in a Large Wireless Sensor Network of Random Size Ruixin Niu, Pramod K.Varshney （Department of Electrical Engineering and Computer Science, Syracuse University, 335 Link Hall, Syracuse, NY 13244-1240, USAAbstract：For a wireless sensor network (WSN) with a random number of sensors, we propose a decision fusion rule that uses the total number of detections reported by local sensors as a statistic for hypothesis testing. We assume that the signal power attenuates as a function of the distance from the target, the number of sensors follows a Poisson distribution, and the locations of sensors follow a uniform distribution within the region of interest (ROI). Both analytical and simulation results for system-level detection performance are provided. This fusion rule can achieve a very good system-level detection performance even at very low signal-to-noise ratio (SNR), as long as the average number of sensors is sufficiently large. For all the different system parameters we have explored, the proposed fusion rule is equivalent to the optimal fusion rule, which requires much more prior information. The problem of designing an optimum local sensor-level threshold is investigated. For various system parameters, the optimal thresholds are found numerically by maximizing the deflection coefficient. Guidelines on selecting the optimal local sensor-level threshold are also provided. Keywords and phrases: wireless sensor networks, distributed detection, decision fusion, deflection coefficient. 引言 近年来，无线传感网络倍受关注，并已成为一个相