Emulation of LTE Link Scenarios Reproducibly Derived from Field-Operational Tests

• Main Authors: Berlt, Philipp, Altinel, Berk, Bornkessel, Christian, Hein, Matthias A.
• Format: Conference Proceeding
• Language: English
• Subjects: Antenna measurements; Measurement techniques; Radio links; Signal generators; Systematics; Throughput; Virtual environments
• ISSN: 2474-2740
• DOI: 10.23919/AMTA55213.2022.9954989

Virtual drive tests using the over-the-air/vehicle-in-the-loop method are becoming an essential part of testing vehicular radio systems. Different approaches ask which link scenarios and channel environments are relevant and should be tested. This paper deals with the systematic evaluation of field-operational tests and the implementation of virtual drive tests of LTE communication links focussing on the performance of the radio link close to the edges of the radio cells, which are identified as a relevant testing scenario. For this purpose, three test drives were performed on each of two test tracks. Close to cell edges the available data throughput is as much as a factor of 10 lower than the maximum available data throughput along the test track and reduced approximately by half compared to the average data throughput in the cell center. Instead of trying to recreate the entire test drive with high accuracy, this approach focusses on recreating the critical parts of a test drive in the laboratory, as these are the most likely to cause radio link failure in real operation. Therefore, the physical parameters in terms of serving signal strength and level of interfering signals were transferred to a wired virtual test, and the data rate was examined again. Despite some systematic differences between real drive test and virtual drive test, which could be clearly identified, it was possible to reproduce the behavior at the cell edge very precisely with deviations smaller than 5 %.