Design & Implementation For Random Pulse And Answer Probability Of DME Simulator

DME(Distance Measuring Equipment)is a kind of secondary RADAR system which can measure the distance from interrogator to fixed responder.It include airborne equipment and ground equipment.Airborne equipment namely Distance Measuring Equipment(DME),at present,DME is a kind of general-purpose avionics equipment equipped in civil aviation plane.The ground equipment is the DME ground beacon,and its main purpose is to transmit a response signal when the DME interrogation signal is received.The DME simulator is a kind of instrument which can simulate the function of DME ground beacon.It is the essential equipment for detecting and testing DME on the ground.The DME simulator can not only transmit DME answer signal,there are many other used to detect and test the function of DME.Generally speaking,the DME simulator has the functions of setting the response probability,setting the random pulse filling rate,setting the output level,setting the pulse code,transmitting power and transmitting frequency.This paper first introduces the background of the paper,and puts forward the structure and tasks of the paper.After a brief introduction of the working principle and working principle of DME simulator and signal characteristics of the DME system,combined with the specific design requirements,analyzes the hardware structure design of the subject,and finally put forward based on the programmable logic device(FPGA)of the DME simulator and answer implementation scheme of random pulse probability.According to the key points and difficulties of the design,the hardware circuit design and the software control logic design of DME simulator are discussed.In this paper,we discuss the principle of pseudo-random number in DME simulator,and discuss how to generate random numbers by linear shift register.The implementation of DME simulator and software design of random pulse answer probability in detail,introduces the data structure of each module of the software design,software and work flow of each module of data transmission.At the end of this paper,the shortcomings of the whole design process are summarized,and the future work is also prospected.This paper realizes the control of the DME simulator random pulse output and the response probability in the laboratory,the test shows that the simulator is random pulse output and response probability control to achieve the design requirements,meet the DME equipment testing and maintenance needs,and has been used.