Distributed detection in wireless sensor networks using a multiple access channel
Distributed detection in wireless sensor networks using a multiple access channel
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DOI：
10.1109/tsp.2006.887563
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发表时间：
2007-03-01
影响因子：
5.4
通讯作者：
Dai, Huaiyu
中科院分区：
文献类型：
--
作者：
Li, Wenjun;Dai, Huaiyu
以相关高斯噪声中确定性信号的检测和独立高斯噪声中一阶自回归[AR(1)]信号的检测为例，研究了具有相关传感器观测值的一维（1- d）传感器网络中的分布式检测问题。与使用一组专用并行接入信道（PAC）将传感器观测数据传输到融合中心的传统方法相比，我们探索了采用共享多接入信道（MAC）的可能性，这大大降低了带宽要求或检测延迟。我们假设局部观测是根据一个受功率约束的函数来映射的。利用大偏差方法，我们证明了对于相关噪声问题中的确定性信号，在特殊选择的映射规则下，MAC融合在平均功率约束（APC）下获得了与集中检测相同的渐近性能，而PAC融合总是存在误差指数损失。在总功率约束（TPC）下，MAC融合仍然导致误差指数随传感器数量呈指数衰减，而PAC融合则不会。对于AR信号问题，我们提出了一种次优MAC映射规则，该规则对几乎所有信噪比（SNR）值下的弱相关信号以及信噪比高或低时的强相关信号执行密切的集中检测。最后，我们表明，虽然缺乏MAC同步总是导致误差指数的下降，但当传感器之间的相位不匹配足够小时，这种下降可以忽略不计。
Distributed detection in a one-dimensional (1-D) sensor network with correlated sensor observations, as exemplified by two problems-detection of a deterministic signal in correlated Gaussian noise and detection of a first-order autoregressive [AR(1)] signal in independent Gaussian noise, is studied in this paper. In contrast with the traditional approach where a bank of dedicated parallel access channels (PAC) is used for transmitting the sensor observations to the fusion center, we explore the possibility of employing a shared multiple access channel (MAC), which significantly reduces the bandwidth requirement or detection delay. We assume that local observations are mapped according to a certain function subject to a power constraint. Using the large deviation approach, we demonstrate that for the deterministic signal in correlated noise problem, with a specially chosen mapping rule, MAC fusion achieves the same asymptotic performance as centralized detection under the average power constraint (APC), while there is always a loss in error exponents associated with PAC fusion. Under the total power constraint (TPC), MAC fusion still results in exponential decay in error exponents with the number of sensors, while PAC fusion does not. For the AR signal problem, we propose a suboptimal MAC mapping rule which performs closely to centralized detection for weakly correlated signals at almost all signal-to-noise ratio (SNR) values, and for heavily correlated signals when SNR is either high or low. Finally, we show that although the lack of MAC synchronization always causes a degradation in error exponents, such degradation is negligible when the phase mismatch among sensors is sufficiently small.