Simulation Of Ground Dynamic Test Environment For Aircraft HF Communication System

High frequency communication is an important means of aircraft communication.During the flight test of a certain type of domestic aircraft,the communication quality is often poor or even unable to communicate,which seriously affects the flight test efficiency of high frequency communication system.However,the current ground test method of HF communication system belongs to static test method,which can not reproduce the channel environment of flight test and verify the remote communication performance of HF communication system on the ground.Therefore,it is necessary to design a ground dynamic test method of high frequency communication system,which can find and solve the problems of airborne high frequency communication system before flight test.Channel environment simulation technology can simulate the signal transmission environment during flight test.It is of great significance to design dynamic test method and build ground dynamic test system based on channel environment simulation technology for flight test of aircraft high frequency communication system.Firstly,based on the characteristics of available communication frequency in HF communication,in order to obtain the available test frequency of ground dynamic test,the prediction of available frequency in HF communication is studied.Aiming at the problem of low short-term prediction accuracy of existing prediction methods,a combined prediction model for short-term prediction of ionospheric critical frequency is established.The combined model is used to predict the critical frequency of Beijing ionospheric station,and the prediction results are compared with other models.Secondly,in order to reproduce the communication environment of flight test and provide test signal for ground dynamic test.The influence of different flight test environments on high frequency communication signals is analyzed,and a complete channel model is built according to these influences,and the model is simulated and verified by human voice signals.Finally,based on the prediction of available frequency of high frequency communication and the research of high frequency channel model,the simulation software of ground dynamic test environment of high frequency communication system is designed and developed.Combined with vector signal source,channel power amplifier,attenuator and other hardware equipment,the ground dynamic test system is built,and the functions of the software and hardware of the system are verified respectively.The results show that: compared with other single models,the short-term prediction combined model of ionospheric critical frequency proposed has higher prediction accuracy;the simulation results of the channel model are consistent with the theory,which can realize the simulation of flight test communication environment;the software module of the ground dynamic test system has complete functions,and the simulation results are consistent with the theoretical analysis,and the vector signal source and signal power of the system are stable The hardware indexes such as rate amplifier and attenuator are normal,and the software and hardware of the system can work together normally.By simulating the channel environment of high frequency communication system flight test,the system realizes the ground dynamic test of high frequency communication system,which not only provides a reference for the scheme demonstration and technology research and development of high frequency communication system,but also further expands the ground test method of high frequency communication system,and improves the efficiency of high frequency communication system flight test.