LDACS1 conformance and compatibility assessment

Abstract

In this paper the results of conformance and compatibility measurements of an L-band Digital Aeronautical Communication System Type 1 (LDACS1) transmitter are presented. The measurements were performed at the Institute of Electrodynamics, Microwave and Circuit Engineering (EMCE) of TU Vienna as well as in the labs of the German air navigation service provider Deutsche Flugsicherung GmbH (DFS) in connection with the SESAR project P15.2.4. Prior to the deployment of any new aviation communication system, the compatibility towards legacy systems has to be confirmed. For this purpose, an LDACS1 transmitter prototype was developed by Frequentis AG/TU Vienna to validate the LDACS1 system specification and prove the spectral compatibility of LDACS1 with the legacy L-band systems (e.g. DME, SSR, and UAT). Previous analysis has indicated that the DME/TACAN-LDACS coexistence is one of the most critical scenarios due to its wide and extensive use in the civil aviation.

LDACS Flight Trials: Demonstration and Performance Analysis of the Future Aeronautical Communications System

“…This frequency planning must also guarantee that legacy systems operating in the L-band, such as the Distance Measuring Equipment (DME), are not affected by the presence of LDACS. Up to now, such spectrum compatibility was only supported by theoretical studies [13] based on laboratory measurements [12]. Our flight trials represent the first real-world compatibility tests between LDACS and the legacy systems operating in the L-band.…”

Impact Assessment of the L-Band Digital Aeronautical Communications System on the Joint Tactical Information Distribution System

“…x Rx , y Rx , h Rx , i.e., for m RL = 0, 1, ..., M RL − 1, a) δ RL mRL,k is obtained using (14), b) the locations of the ASs are generated randomly and uniformly within the cell limits, c) the distance from each ASs to the JU Rx is computed using (10) and ω RL mRL,k is obtained using (16), d) the ω RL mRL,k corresponding to any transmission from an AS not fulfilling (9) is set to 0, 7) M RL RL LDACS baseband signals g RL mRL with a duty cycle D are generated, 8) i is obtained using (5), 9) r is obtained using (4), 10) r is processed by the implemented JTIDS-type receiver and the BER is computed. Note that we simplify our analysis by considering that full-tiles transmitted from different ASs within the same cell are received synchronously by the JU Rx , i.e., they do not overlap with each other, which is only true if the JU Rx is colocated with the GS controlling the cell.…”

“…As DME operates in the frequency range 962-1213 MHz, covering practically the entire band where LDACS may operate, compatibility tests between LDACS and DME were considered crucial. In [10], the impact of LDACS on DME was measured and conditions for the operation of LDACS were extracted, under which the functionality of DME is not harmfully affected. Conversely, the impact of DME on LDACS was analysed in [11] and effective interference mitigation schemes for LDACS receivers have been proposed, e.g., in [12], [13].…”

L-band Digital Aeronautical Communications System (LDACS) - Technical Validations in SESAR2020

“…LDACS technology development started in the SESAR P15.02.04 project, based on an initial LDACS specification [2], and is currently continued in the SESAR2020 PJ14 project. LDACS TX prototypes, which were produced in SESAR P15.02.04, were validated against [2] with the results provided in [5].…”

“…The testbed comprises one AS (7) and two ground-stations, GS1 (4) and GS2 (5). A single physical PC -VM host (1) -has been used for implementing several functions: Testbed Manager (TBM), Access Router (AC-R), and Ground End System (G-ES).…”