A Preliminary Compatibility Analysis Between LDACS and a Portable ADS-B Receiver

This study investigates the compatibility between L-band Digital Aeronautical Communications System (LDACS) and Automatic Dependent Surveillance-Broadcast (ADS-B). A detailed link budget model is established to quantify the impact of in-band and out-of-band interference of LDACS on ground ADS-B receivers. Based on a portable commercial ADS-B receiver, a testbed is built and laboratory tests are conducted. The effects of LDACS with various signal powers on ADS-B message reception rates are investigated. Based on the laboratory test, it is show that the LDACS signals begin to affect ADS-B reception at a transmission power of -62.8 dBm, implying that an isolation greater than 106.8 dB is necessary to avoid interference when assuming the LDACS ground station transmits at its maximum power. By contrast, the conservatively set parameters of the link budget model predicted a required isolation of 130.2 dB, demonstrating a margin of safety. Future work will focus on refining the interference model and exploring mitigation techniques to enhance system coexistence.