Research And Simulation Of Dynamic Signal Generation And Wireless Channel In Complex Electromagnetic Environment

In the modern informationized battlefield,due to the large amount of electronic information equipment used by the enemy and ours,and the rapid growth of civilian information facilities,the electromagnetic signals in t he battlefield space are very dense;at the same time,the wireless transmission channel formed by the complex and unknown geographical environment of the battlefield leads to There are all kinds of declines that are difficult to estimate.These two factor s constitute a very complex dynamic electromagnetic environment.The characteristics of mobile wireless channels have an important impact on the performance of mobile communication systems.Mobile channel modeling and simulation are of great significance t o the development of mobile communication systems.Therefore,research on mobile channel modeling and simulation has important theoretical significance and practical application value.Based on the characteristics of radio wave propagation,this paper anal yzes and studies the main parameters of the radio wave propagation model and wireless channel characteristics,focusing on the mobile small-scale fading channel model,studying the characteristics of flat fading channels and frequency-selective channels,and designing based on The mobile wireless channel emulator of FPGA performs software and hardware simulation at the same time for comparison and verification.This article mainly did the following work:1.The signal model based on the unified architecture is studied,and a general signal generation scheme based on the hardware platform is given,which can complete the generation of signals of different modes.2.The three main types of channel effects on wireless signals are studied: path loss,shadow fading,and multipath fading;the basic model of wireless communication propagation environment and mobile wireless communic ation channel simulation is analyzed,and the use of sine wave superposition method and shaping filtering is described.The concrete realization method of the channel-determined simulation model established by the device method.3.Matlab simulation was carried out on the characteristics of the mobile wireless channel,and the simulation results were compared with the channel model to determine the feasibility of the channel model.4.Completed the design and implementation of flat fading channel and frequency selective channel on FPGA,and analyzed the key technologies and implementation methods.This design can simulate the main character istics of the wireless channel in real time under narrow-band signal conditions,such as multipath effect,Doppler effect,Rayleigh fading,etc.,and its main technical indicators have met the design requirements.At the same time,the design structure is simple,the parameters are adjustable,easy to expand,strong versatility,and convenient for performance testing.