In this study, the authors propose a new time-of-arrival (ToA) algorithm for positioning in the physical layer of narrowband Internet-of-Things (NB-IoT) technology. This algorithm estimates the ToA of transmitted narrowband positioning reference signals (NPRSs) by detecting the first valid tap of estimated power delay profile (PDP). They estimate the PDP as well as the noise power in the time domain via inverse Fast Fourier transformation of received frequency-domain NPRSs. The accuracy of the estimated noise power is crucial in the ToA estimation since the SNR is extremely low in typical NB-IoT scenarios. The simulations show that the proposed ToA estimation method outperforms the conventional method and performs well in various scenarios.

中文翻译：

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NB-IoT物理层中的到达时间估计算法

在这项研究中，作者提出了一种新的到达时间（ToA）算法，用于在窄带物联网（NB-IoT）技术的物理层中进行定位。该算法通过检测估计的功率延迟曲线（PDP）的第一个有效抽头来估计发送的窄带定位参考信号（NPRS）的ToA。他们通过接收到的频域NPRS的快速傅里叶逆变换来估计PDP以及时域中的噪声功率。估计噪声功率的准确性在ToA估计中至关重要，因为在典型的NB-IoT场景中SNR极低。仿真结果表明，提出的ToA估计方法优于传统方法，并且在各种情况下均具有良好的性能。