Time-of-Arrival Estimation Based on Information Theoretic Criteria
Time-of-Arrival Estimation Based on Information Theoretic Criteria
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DOI：
10.1109/tsp.2013.2239643
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发表时间：
2013-04-01
影响因子：
5.4
通讯作者：
Chiani, Marco
中科院分区：
文献类型：
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作者：
Giorgetti, Andrea;Chiani, Marco
使用无线技术精确定位标签的可能性对于物联网中的几个新兴应用非常重要。利用超宽带(UWB)脉冲无线电(IR)系统可以获得精确的测距，在该系统中传输短脉冲，并在接收端估计其到达时间(TOA)。由于噪声和多径的存在，估计器具有通过也有信号分量的时间间隔来区分接收波形仅由噪声引起的时间间隔的困难任务。常见的低复杂度方法使用能量检测器(ED)，其输出与阈值进行比较，以区分仅包含噪声的时间间隔和包含信号加噪声的时间间隔。这些方法的最佳门限设计需要了解信道冲激响应和接收器噪声功率。我们提出了一种不同的方法，其中TOA估计基于信息论标准(ITC)的模型选择。由此产生的TOA算法不使用阈值，并且不需要关于通道或噪声功率电平的任何信息。这些盲的、通用的TOA估计器在完全未知的多径信道和存在未知功率的噪声的情况下，与理想的基因辅助方案相比表现出了优异的性能。
The possibility to accurately localize tags by using wireless techniques is of great importance for several emerging applications in the Internet of Things. Precise ranging can be obtained with ultra wideband (UWB) impulse radio (IR) systems, where short impulses are transmitted, and their time-of-arrival (ToA) is estimated at the receiver. Due to the presence of noise and multipath, the estimator has the difficult task of discriminating the time intervals where the received waveform is due to noise only, by those where there are also signal components. Common low-complexity methods use an energy detector (ED), whose output is compared with a threshold, to discriminate the time intervals containing noise only from those containing signal plus noise. Optimal threshold design for these methods requires knowledge of the channel impulse response and of the receiver noise power. We propose a different approach, where ToA estimation is based on model selection by information theoretic criteria (ITC). The resulting ToA algorithms do not use thresholds, and do not require any information about the channel or the noise power level. These blind, universal ToA estimators show, for completely unknown multipath channels and in the presence of noise with unknown power, excellent performance when compared with ideal genie-aided schemes.