A2: Metrology of Multi-Dimensional Channel Sounding

A2项目第一阶段的主要目标是“研究和比较实时宽带测深仪的结构，并开发校准程序，以便能够利用所使用的测量设备以最小可能的失真估计多径传播的几何模型”。在已取得成果的基础上，我们将在第二阶段致力于改进的探测仪架构，以克服我们以前设置的限制，并实现雄心勃勃的计量级太赫兹无线电系统评估。首先，我们将受益于任意波形处理的灵活性。多载波信号设计和预失真方案将改进探测仪校准程序，提高发射功率效率。另一个优势来自多载波激励信号再现典型的ofdm和SC-FDMA通信波形的预定义包络统计的能力。这是用来估计在某些应用场合下射频子系统的非线性诱发失真行为。其次，预期的相干多通道射频架构为太赫兹探测仪的应用提供了前所未有的功能。在第一阶段结束时，我们将拥有一个2x2的四极化收发信机接口，频率为300 GHz。这将进一步用于演示来自项目A1的正典参考人工制品的极化签名的识别。这将为太赫兹通信的综合通信和传感应用铺平道路，例如基于雷达的SLAM导航(SLAM：同时定位和测绘)。另一个重要步骤是使用具有四个相干下变频器的4单元接收阵列。因此，利用任意波形无线电接口的实时能力，我们将在动态场景中演示真正的联合延迟/多普勒/DOA分辨率(DOA：到达方向)。这为将多维引入时变、定向无线电系统的系统计量开辟了新的视角。此外，我们将把多维方法扩展到DOD估计(DOD：出发方向)。我们将演示联合DOA/DOD分辨率对于正确描述波传播的双向特性以及对在链路两侧使用定向天线(尤其是阵列)的太赫兹收发器进行全面的系统级评估是必要的。最后，计划中的设置将允许模拟分布式多链路和多跳网络结构。这为这些先进的太赫兹无线电系统的计量级评估提供了新的视角。第三，我们将进一步发展基于模型的估计过程，以处理丢失载波和稀疏载波分配，以及处理表现出色散响应和特征极化特征的扩展对象。

The major objective in the first phase of the project A2 was “the study and comparison of real-time broadband sounder architectures and the development of calibration procedures that allow the estimation of the geometric model of multipath propagation with the least possible distortion by the measurement device used”. On the basis of the results achieved, we will be working in the second phase on an enhanced sounder architecture that overcomes the limitations of our former setup and enables ambitious metrology-grade THz radio system evaluations. Firstly, we will profit from the flexibility of arbitrary waveform processing. Multicarrier signal design and predistortion schemes will lead to enhanced sounder calibration procedures and increased Tx power efficiency. Another advantage comes from the capability of multicarrier excitation signals to reproduce predefined envelope statistics of typical OFDM and SC-FDMA communication waveforms. This is used to estimate the nonlinear induced distortion behavior of RF subsystems in certain application situations. Secondly, the intended coherent multichannel RF-architecture offers unprecedented features for THz sounder application. Already at the end of the first phase, we will have a 2x2 quad-polarimetric transceiver radio interface at 300 GHz available. This will be further used to demonstrate the identification of polarimetric signatures of canonic reference artifacts from project A1. This shall pave the way for integrated communication and sensing applications of THz communications, e.g. radar based SLAM navigation (SLAM: Simultaneous Localization and Mapping). Another important step is the use of a 4-element receive array which becomes available with four coherent down converters. Thereby and with the real-time capability of the arbitrary waveform radio interface, we will demonstrate true joint delay/Doppler/DoA resolution (DoA: direction of arrival) in dynamic scenarios. This opens new perspectives to introduce multidimensionality to system metrology of time-variant, directive radio systems. Moreover, we will extend the multidimensionality approach to DoD estimation (DoD: direction of departure). We will demonstrate that joint DoA/DoD resolution is necessary for a correct bidirectional characterization of wave propagation and a comprehensive system level evaluation of THz transceivers that use directive antennas, most notably arrays, at both sides of the link. Finally, the planned setup will allow emulating distributed multilink and multi-hop network structures. This offers new perspectives for metrology-grade evaluation of these advanced THz radio systems. Thirdly, we will further developed our model-based estimation procedure to deal with missing carriers and sparse carrier allocation and to handle extended objects showing a dispersive response and a characteristic polarimetric signature.