A2: Metrology of Multi-Dimensional Channel Sounding

• Applicants: Professor Dr.-Ing. Giovanni del Galdo; Privatdozent Dr.-Ing. Thomas Kleine-Ostmann; Professor Dr.-Ing. Thomas Kürner; Professor Dr.-Ing. Reiner Thomä
• Subject Area: Communication Technology and Networks, High-Frequency Technology and Photonic Systems, Signal Processing and Machine Learning for Information Technology
• Term: since 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 403579441

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.

• DFG Programme: Research Units
• Subproject of: FOR 2863: Metrology for THz Communications