Time variant directional multi-link channel sounding and estimation for V2X. - In: 2023 IEEE 97th Vehicular Technology Conference (VTC2023-Spring), (2023), insges. 5 S.
We present our new scalable multi-channel and multi-node sounder, the ILMSound G3 . It is configurable in terms of the number of switched Tx and parallel Rx nodes. The basic structures of the Tx and Rx nodes are given with consideration of the measurement system requirements.The ILMSound G3 is validated via a proof of concept measurement at 2.53 GHz in an urban environment. The system was configured as a sounder with two Tx nodes and one Rx node, which records two MIMO links simultaneously. Each node uses an antenna array. The transmitters were moved by cars whereas the receiver was elevated 20 m above the ground by a lifting platform acting as a base station. The used system configuration results in a snapshot rate of approx. 0.5 kHz, which covers the expected time variance of the chosen environment.The measurement results were analyzed using HRPE, providing a parametric description of the specular propagation paths of the radio channel per measurement link. Each estimated path is described by its directions of departure and arrival, delay, Doppler shift, and fully polarimetric complex path weights.
https://doi.org/10.1109/VTC2023-Spring57618.2023.10199213
Sensing resources reduction for vehicle detection with integrated sensing and communications. - In: 2023 IEEE 97th Vehicular Technology Conference (VTC2023-Spring), (2023), insges. 5 S.
Integrated Sensing and Communications (ISAC) aims at incorporating radar and communications functionalities into a single system, achieving higher spectral efficiency through their joint operation. This paper proposes a methodology for reducing resource elements and scanning beams used in the target detection stage of ISAC. Building upon the well-known symbol domain Orthogonal Frequency Division Multiplexing (OFDM) ISAC processing algorithm, its relevant characteristics and limits are considered to minimize the periodicity of sensing resource elements. Moreover, a methodology for finding the required beams to sense a scenario using the radar range equation in a link-budget analysis is proposed and later illustrated via simulations. The simulations show that it is possible to cover a road scenario using a limited number of beams and resource elements from a New Radio (NR) OFDM frame.
https://doi.org/10.1109/VTC2023-Spring57618.2023.10199358
Fill level measurement of low-permittivity material using an M-sequence UWB radar. - In: International journal of microwave and wireless technologies, ISSN 1759-0795, Bd. 15 (2023), 8, S. 1299-1307
Due to increasingly complex and automated manufacturing processes, the demands on the control parameters of these processes are also increasing. One parameter is the fill quantity of, e.g., liquids in production plants, whose precise determination is of ever-growing importance. Up to now, the exact level of determination under difficult conditions, such as high ambient temperatures, has been a particular challenge. This paper demonstrates a novel method by which an M-sequence UWB radar can determine levels of low-permittivity materials in small metal containers. For this purpose, hot melt is used as an example. Thus, the influence of large temperature differences on the long-term stability of level measurement can also be investigated. The measurements show that the level of hot melt can be measured to be long-term stable with an accuracy of better than 3 mm. Furthermore, the precise determination of the empty state is highly important for many applications. For this reason, this paper shows a method for determining the empty state without complex calibration procedures. For the empty level indication, an accuracy of up to 0.5 mm could be achieved for molten hot glue and 3% of the tank volume, independent of the shape or aggregate state of the medium.
https://doi.org/10.1017/S1759078723000739
Optimum access-point constellation for indoor time difference of arrival positioning. - In: 2023 IEEE/ION Position, Location and Navigation Symposium (PLANS), (2023), S. 1234-1240
The availability of ubiquitous location services is a highly desirable feature for many upcoming applications in the realm of the Internet of Things (IoT), including asset tracking, navigation services especially in indoor environments such as shopping centers, or emergency people tracking in schools, hospitals, and prisons. While outdoor positioning is perfectly covered by Global Navigation Satellite Systems (GNSS), indoor positioning services, except for a few pioneer projects, did not hit the mainstream yet. At first, this is surprising, as the underlying technology has been known for years and solutions already exist based on WiFi or Bluetooth beacons. A major problem is, that the locations of those beacons need to be highly tailored to the specific indoor floorplan for high positioning accuracies, which directly contradicts the need for a cheap installment. Picking up this challenge, we present a methodology for fast optimization of access point locations in indoor environments, maximizing coverage and positioning accuracy that will facilitate a broad deployment of indoor positioning systems.
https://doi.org/10.1109/PLANS53410.2023.10140137
Efficient phased array radiation pattern evaluation for 5G and SatCom On-The-Move (SOTM) applications. - In: 17th European Conference on Antennas and Propagation (EuCAP 2023), (2023), insges. 5 S.
In satellite communications, it is becoming challenging to provide the tracking performance which is required for Non-Geostationary Orbit (NGSO) constellations with the traditional Satellite Communications (SatCom) On The Move (SOTM) terminal structure which employs bulky parabolic antennas. On the other hand, in terrestrial networks, the single omnidirectional communication with User Equipment (UE) does not provide enough throughput to fulfill the need for higher speed connections. As a consequence, manufacturers started to invest in developing new terminals which use phased array antennas to enable beamforming to increase the directivity and null the interference in terrestrial networks and to provide rapid tracking performance as well as seamless handovers in SOTM. However, this generates new challenge as these antennas change beam patterns depending on the beam steering angle. It is not trivial to evaluate the performance of beamforming antennas since the measurement of the high number of beam patterns that the phased array can form in all directions is time consuming. In this paper, we propose a methodology to measure a large number of beam patterns of a phased array antenna in a more time efficient approach compared to traditional antenna measurement methods. The measured patterns can be used to evaluate the antenna performance and capabilities in different conditions and verify the terminal ability to fulfill the requirements specified by the standards.
https://doi.org/10.23919/EuCAP57121.2023.10132956
Receiver bandwidth extension beyond Nyquist using channel bonding. - In: 17th European Conference on Antennas and Propagation (EuCAP 2023), (2023), insges. 5 S.
Current and upcoming communication and sensing technologies require ever larger bandwidths. Channel bonding can be utilized to extend a receiver’s instantaneous bandwidth beyond a single converter’s Nyquist limit. Two potential joint front-end and converter design approaches are theoretically introduced, realized and evaluated in this paper. The Xilinx RFSoC platform with its 5 GSa/s analog to digital converters (ADCs) is used to implement both a hybrid coupler based in-phase/quadrature (I/Q) sampling and a time-interleaved sampling approach along with channel bonding. Both realizations are demonstrated to be able to reconstruct instantaneous bandwidths of 5 GHz with up to 49 dB image rejection ratio (IRR) typically within 4 to 8 dB the front-ends’ theoretical limits.
https://doi.org/10.23919/EuCAP57121.2023.10133262
Measurement testbed for radar and emitter localization of UAV at 3.75 GHz. - In: 17th European Conference on Antennas and Propagation (EuCAP 2023), (2023), insges. 5 S.
This paper presents an experimental measurement platform for the research and development of unmanned aerial vehicles (UAVs) localization algorithms using radio emission and reflectivity. We propose a cost-effective, flexible testbed made from commercial off-the-shelf (COTS) devices to allow academic research regarding the upcoming integration of UAV surveillance in existing mobile radio networks in terms of integrated sensing and communication (ISAC). The system enables nanosecond-level synchronization accuracy and centimeter-level positioning accuracy for multiple distributed sensor nodes and a mobile UAV-mounted node. Results from a real-world measurement in a 16 km^2 urban area demonstrate the system’s performance with both emitter localization as well as with the radar setup.
https://doi.org/10.23919/EuCAP57121.2023.10133118
Spatial/temporal characterization of propagation and blockage from measurements at sub-THz in industrial machines. - In: 17th European Conference on Antennas and Propagation (EuCAP 2023), (2023), insges. 5 S.
In the present paper we introduce novel ultra-wideband (UWB) dual-polarized double-directional measurements at sub-THz (300 GHz) in an access point to inside of machine application in an industrial scenario. The results show a sparse spatial/temporal channel with multiple paths from the different metallic objects and their influence on polarization. In addition, different LOS blockage situations were investigated, showing the presence of alternative paths for communications.
https://doi.org/10.23919/EuCAP57121.2023.10133323
Measurement-based analysis of multi-band assisted beam-forming at mmWave in industrial scenarios. - In: 17th European Conference on Antennas and Propagation (EuCAP 2023), (2023), insges. 5 S.
The mmWave and sub-THz bands are foreseen as candidates to achieve the data-rate demands in the beyond 5G and 6G wireless communication networks. The co-existence of multiple radio interfaces at several bands enables data fusion and the utilization of the similarities and differences on propagation and system properties for communication and sensing applications. MmWave radio interfaces rely on directive beams that require high training overhead for beam steering. Sensors in the network infrastructure and co-located radio interfaces at sub-6 GHz and mmWave can be used to assist the beam-forming process at mmWave. In the present paper we investigate the performance of multi-band assisted beam-forming in an industrial environment. We empirically demonstrate from real-world measurements that even in NLOS, the direction of the beams estimated at sub-6 GHz can be used to established a link at mmWave.
https://doi.org/10.23919/EuCAP57121.2023.10133694
Reduction of mutual coupling between dual-polarized antenna elements using defected ground structures. - In: 17th European Conference on Antennas and Propagation (EuCAP 2023), (2023), insges. 5 S.
To accurately model a communication channel using channel sounding technique, having dual-polarized antenna elements and low mutual coupling between them is required. In this work a Defected Ground Structure (DGS) is proposed to reduce the mutual coupling between two dual polarized mmWave antenna elements in an array structure. The defected ground is made of etched C-shape slots. The presence of the DGS has a strong impact on H-plane coupling where a suppression of 35 dB is achieved, while the reduction of E-plane coupling is about 4 dB. The unwanted effect on the radiation patterns is negligible and the back radiation is not increased.
https://doi.org/10.23919/EuCAP57121.2023.10133636