Combination of measurement and simulation for fast virtual drive testing. - In: 2023 IEEE International Symposium on Antennas and Propagation (and USNC-URSI Radio Science Meeting), (2023), S. 25-26
Virtual Drive Test (VDT) is an area of great interest for both scientific research and industry. The objective of VDT is to emulate a real-world communication testing by approximation of defined conditions. VDT can be performed in measurement facilities with over-the-air approaches and channel emulation techniques [1] [2], by simulation-based software-in-the-loop tests [3] or by combining measurement and simulation [4]. For all possible solutions, the challenge of the scientific community is to look for an automated, controllable, repeatable, and reliable procedure, which can considerably reduce testing time and costs. In this paper we present a new VDT technique to evaluate the V2X communications performances based on the combination of measurement and simulation. In particular, the radiation performance of a DUT representing the antenna under test installed on a vehicle is tested in a measurement facility, the radiation pattern (vehicle equipped by the antenna) is integrated in a simulation of a realistic scenario to reproduce a real-world communication testing. The accuracy of the method is validated by comparison with results of measured data from Field Operational Test (FoT) of LTE links [5] [6].
https://doi.org/10.1109/USNC-URSI52151.2023.10237776
Kommunikationsnetze und -technik an der Technischen Universität Ilmenau. - In: 17. Ilmenauer TK-Manager Workshop, (2023), S. 15-16
https://www.db-thueringen.de/receive/dbt_mods_00057781
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
PCIMS: plenary centralized intersection management scheme for heterogeneous connected vehicles. - In: 2023 IEEE International Conference on Omni-Layer Intelligent Systems (COINS), (2023), insges. 6 S.
This paper proposes a novel plenary centralized intersection management scheme (PCIMS) for a non-signalized intersection. Our contributions are fourfold. First, we take into account vehicle heterogeneity by integrating various vehicle classes in the system. Second, we consider some key elements in the scheduling mechanism such as vehicle types, intersection rules and road priorities. Third, we discuss the significant role of different road conditions, specific vehicles behavior and safety parameters in the traffic safety. Forth, in addition to the traffic safety assurance, we demonstrate the superiority of the system performance over conventional traffic lights (TLs) in several scenarios with congested and sparse traffic in terms of average travel time (ATT), packet loss rate (PLR), channel busy rate (CBR), intersection busy time (IBT), and throughput.
https://doi.org/10.1109/COINS57856.2023.10189259
Plenary autonomous intersection management protocol for heterogeneous connected vehicles. - In: ICUFN 2023, (2023), S. 334-336
This paper proposes a centralized autonomous intersection management scheme for heterogeneous connected vehicles (HCVs). Contributions of this work are as follows. First, we sustainably classify heterogeneous vehicles with their distinctive safety-related characteristics. Second, we conduct a safe and efficient coordination algorithm with respect to some criteria such as vehicle types, road priorities and right of way rules. Third, we consider the impact of different road conditions, vehicle characteristics, load, and braking technology on the system performance. Forth, we demonstrate the efficiency of the system under various traffic densities with symmetric and asymmetric vehicle distribution. Besides, system performance is to be compared with traffic lights (TLs) scenarios in terms of throughput, average travel time (ATT), intersection busy time (IBT), channel busy rate (CBR), and packet loss rate (PLR) in various road conditions.
https://doi.org/10.1109/ICUFN57995.2023.10200347
Distributed coordinated beamforming for RIS-aided dynamic TDD systems. - In: WSA & SCC 2023, (2023), S. 66-71
We consider the joint design of the active and passive beamforming for a reconfigurable intelligent surface (RIS) aided dynamic time-division-duplexing (DTDD) wireless network. An alternating optimization (AO) method is proposed. To reduce the high signaling overhead involved in the centralized solution for the active beamforming design, a distributed coordinated beamforming based on the alternating direction method of multipliers (ADMM) is proposed. The Semidefinite Programming (SDP) technique is adopted for the design of the passive reflection matrix of the RIS. Our design objective is to maximize the minimum signal-to-interference-plus-noise ratio (SINR) of the downlink users while satisfying the total power constraint of the downlink base stations and guaranteeing that the maximum interference seen by the uplink users due to the transmission of the downlink cells is below a pre-defined level. Our numerical results demonstrate that the proposed algorithm converges to the centralized solution in a reasonable number of iterations.
Deep-LaRGE: higher-order SVD and deep learning for model order selection in MIMO OFDM systems. - In: WSA & SCC 2023, (2023), S. 43-48
Despite the large volume of research on the field of model order selection, finding the correct rank number can still be challenging. Propagation environments with many scatters may generate channel multipath components (MPCs) which are closely spaced. This clustering of MPCs in addition to noise makes the model order selection task difficult for wireless channels which can directly impact user equipment (UE) throughput, e.g., wrong lower rank approximation for channel estimation via Unitary ESPRIT. In this paper, we exploit the multidimensional characteristics of MIMO orthogonal frequency division multiplexing (OFDM) systems and propose an artificial intelligence and machine learning (AI/ML) method capable of determining the number of MPCs with a higher accuracy than state of the art methods in almost coherent scenarios. Moreover, our results show that our proposed AI/ML method has an enhanced reliability as the threshold for signal singular value selection is 80 %.
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
Emulation of realistic satellite constellations for GNSS receiver testing in virtual environment. - In: 17th European Conference on Antennas and Propagation (EuCAP 2023), (2023), insges. 5 S.
Automotive navigation is key for modern traffic, which necessitates robust satellite navigation receivers. Distributed antenna arrays can be advantageous with their beam-and null-steering capabilities, however, testing them in the field is resource-intensive and non-repeatable. Therefore, evaluating them in virtual electromagnetic environments is reasonable prior to scheduling field-operational tests. Thereby the challenge arises that the angles-of-arrival of satellite signals deviate from those of their corresponding antennas due to the fixed orbital rotation of satellites and mechanical limitations of physical antenna placements. This discrepancy creates an unrealistic satellite constellation, eventually affecting directions-of-arrival estimation of incident signals which is crucial for interferer suppression. A Matlab tool was implemented to locate satellites near desired transmitter positions and numerically alter their orbital parameters to minimize their angular deviation from respective transmitters. Employing the tool, a realistic virtual satellite constellation with less than 1 degree deviation was emulated and experimentally verified for the test facility.
https://doi.org/10.23919/EuCAP57121.2023.10133419
Exposure change at two mobile radio base stations due to upgrading with 5G. - In: 17th European Conference on Antennas and Propagation (EuCAP 2023), (2023), insges. 5 S.
Radio frequency exposure measurements in the surroundings of two mobile radio base stations were performed before and after their upgrade to 5G to investigate exposure changes. The measurements were carried out in an urban environment in Berlin, and a 5G Dynamic Spectrum Sharing (DSS) base station and a 5G massive MIMO base station were investigated. At the first base station, a previous UMTS system was replaced by a DSS system (LTE and 5G share common resources) with unchanged total transmission power. The maximum possible exposure at five out of six measurement points remains unchanged within the measurement uncertainty. At the second base station under investigation, a 5G massive MIMO antenna technology was additionally installed to an existing mobile radio system. Here, maximum possible exposure increases of 6 to 11 dB occur at the investigated measurement points. A parallel recording of the 5G instantaneous exposure at the massive MIMO station shows that the exposure without provoking traffic load (signalization only) and at low traffic load exploits only 5-10% of the maximum exposure in terms of field strength.
https://doi.org/10.23919/EuCAP57121.2023.10133212