Research On The Airborne Data Link System Of Civil Aircraft

As the primary means of air-ground data communications, air-ground data link systems havebeen widely used in civil aviation system. Air-ground data link system is currently mainly used foraircraft communications addressing and reporting system, which is ACARS. Despite the ACARSused in Chinese civil aviation for many years and achieving good results, its core technology isstill in the hands of a few companies abroad. However, these machines offer contained within theproduct of ACARS, the inherent shortcomings of the original message is not open, a seriousimpediment to domestic airlines for ACARS downlink packet-depth research and secondarydevelopment. Given this, it is necessary to carry out domestic airborne ACARS system-relatedresearch.According to the unit actual needs, this paper constructs the airborne ACARS based on theARINC-618and the ARINC-429. This topic mainly studies the ACARS message format, encodingand modulation demodulation scheme, and discusses in detail message CRC checking principle,calculation method and error correction principle; ARINC-429bus data transfer strategy, thesignal characteristic and coding decoding scheme. And on this basis, the research designs anddevelops with ARM and DSP as the processing core, meets the requirements of the ARINC-429bus specification airborne ACARS demodulation unit. At the same time, in order to meet therequirements of ACARS principle and related technical validation, the paper builds by inertialnavigation system for data source excitation unit ARINC-429bus and the ground of the airborneACARS technology used for validation. Actuator element can simulate inertial navigationinformation generated by the system, and through the ARINC-429bus transmission to theairborne ACARS modulation demodulation unit, through ACARS message encoding, downwardmessage into accord with ARINC-618protocol, the signal modulation, sending to the airborneVHF radio; RGS uplink packet will be sent by airborne ACARS demodulation unit demodulationand decoding. System test in the laboratory environment verifies the validity of the messagetransmission.