Hardware Design Of Multi-target Radar Signal Simulation In TCAS Comprehensive Test System

The Traffic Collision Avoidance System(TCAS)is an important avionics equipment that can monitor the surrounding airspace during the flight of the aircraft and issue a hazard warning when there is a danger of collision.It can also guide the pilot to make evasive movements of ascent or descent in the vertical direction by manipulating the aircraft.In order to meet the verification needs of the R&D process,to find and eliminate problems before the plane takes off,and to ensure the stable operation of the equipment,air collision avoidance system test equipment is required to complete the corresponding test work.According to the actual testing needs of TCAS equipment,this paper proposes a design scheme using three FPGAs + three RF transceiver architecture based on software radio technology,which realizes the signal simulation function of 568 static targets and32 dynamic targets.1.The thesis first elaborates the development status of the TCAS system and the research status of the TCAS integrated test system.Then the whole work flow of the TCAS system is analyzed,and the special communication format of the air collision avoidance system in the communication process is introduced.Based on this,a method is designed to store 600 targets in three FPGAs respectively,and divide the 200 targets in each FPGA into four storage modules,and each storage module stores 50 targets to achieve multi-target design.2.The hardware circuit is designed by using FPGA as the main control module and cooperating with PCI9054 to realize the bridge communication with the host computer,and using AD9361 as the radio frequency transceiver to realize the conversion of digital baseband signal and radio frequency signal.Then cooperate with the clock module to generate a high-stability clock signal,and the power module provides a stable power supply voltage to meet the hardware design requirements.3.The hardware logic module design includes the realization of bridge communication with the host computer through the CPCI interface module,and the decoding of the received inquiry/response signal to extract effective information through the signal receiving and decoding logic module.The TCAS transceiver host test needs to realize effective target search through multi-target parallel search logic according to the effective information,and realize the conversion of target height,distance,and orientation information through the preprocessing module of the extracted target information.The baseband signal encoding module realizes the baseband signal encoding of the response signal and the interrogation signal.Finally,the entire design was verified by building a test platform.Through verification,the design can realize the interrogation signal decoding,and based on the interrogation information,the response signals of 568 static targets and 32 dynamic targets are simulated.This design can simulate and generate the required interrogation signal according to the setting of the host computer,and realize the receiving and decoding of the response signal.