USRP Testbed and Performance Analysis of New Reconfigurable LDACS In Presence of DME Interference

International audienceExisting VHF band based air-to-ground communication (A2GC) is suffering from severe congestion especially in Europe and the US where air-traffic has increased significantly in the last decade. To overcome this problem, a new L-band digital aeronautical communication system (LDACS) is being explored by ICAO. Recently, we proposed reconfigurable filtered OFDM based LDACS (Ref-OFDM) which has the potential to improve the spectrum efficiency of existing OFDM based LDACS. In this paper, we develop an experimental setup using universal software radio peripherals (USRPs) and analyze the performance of these two LDACS. The comparison is made in terms of interference to the legacy distance measuring equipment (DME) channels in L-band and BER for various channel conditions. Specifically, we analyze the performance by varying three parameters related to the LDACS/DME transmitter and receiver: 1) Altitude, 2) Distance, and 3) DME antenna gain. We also consider line-of-sight (LOS) as well as non-LOS paths. The proposed Ref-OFDM performs superior in all considered scenarios, and experimental results closely match the simulation results making Ref-OFDM based LDACS as an attractive alternative to the next generation LDACS