Non-coherent ToA estimation for UWB multipath channels using max-eigenvalue detection
Non-coherent ToA estimation for UWB multipath channels using max-eigenvalue detection
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DOI：
10.1109/icc.2012.6364618
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发表时间：
2012-06
期刊：
影响因子：
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通讯作者：
W. Shi;R. Annavajjala;P. Orlik;A. Molisch;Mari Ochiai;A. Taira
中科院分区：
文献类型：
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作者：
W. Shi;R. Annavajjala;P. Orlik;A. Molisch;Mari Ochiai;A. Taira
由于超宽带(UWB)无线传播信道具有很好的时延分辨率，可以分辨出大量的多径分量(MPC)，而最先到达的MPC可能不是最强的。这使得基本上依赖于确定第一个MPC的到达时间的到达时间(TOA)估计具有极大的挑战性。在这篇文章中，我们考虑了在中等采样率和不知道脉冲形状的情况下，给出了一些测量试验的非相干TOA估计。所提出的TOA估计是基于检测移动时延窗口中信号的存在，使用窗口内信号的样本协方差矩阵的最大特征值作为检验统计量。我们证明了能量检测可以看作是特征值检测的特例。由于以下原因，最大特征值检测(MED)通常具有优越的性能：1)MED收集的噪声较少，即仅包含在信号空间中的噪声；2)如果多个通道抽头落入时间窗口，则MED检测器可以收集所有这些通道的能量。仿真结果证实，在IEEE 802.15.3a和802.15.4a信道中，MED的性能优于能量检测。最后，从仿真和随机矩阵理论两方面对MED阈值的选取进行了研究。
Due to the fine delay resolution in ultra-wideband (UWB) wireless propagation channels, a large number of multipath components (MPC) can be resolved; and the first arriving MPC might not be the strongest one. This makes time-of-arrival (ToA) estimation, which essentially depends on determining the arrival time of the first MPC, highly challenging. In this paper, we consider non-coherent ToA estimation given a number of measurement trials, at moderate sampling rate and in the absence of knowledge of pulse shape. The proposed ToA estimation is based on detecting the presence of a signal in a moving time delay window, by using the largest eigenvalue of the sample covariance matrix of the signal in the window as the test statistic. We show that energy detection can be viewed as a special case of the eigenvalue detection. Max-eigenvalue detection (MED) generally has superior performance, due to the following reasons: 1) MED collects less noise, namely only the noise contained in the signal space, and 2) if multiple channel taps fall into the time window, the MED detector can collect energy from all of them. Simulation results confirm that MED outperforms the energy detection in IEEE 802.15.3a and 802.15.4a channels. Finally, the selection of the threshold of the MED is studied both by simulations and by random matrix theory.