Design And Implementation Of Composite Fading Channel Simulator

UAVs play an irreplaceable role in disaster relief,military strikes,or other high-risk situations.In these missions,the UAV's communication measurement and control system plays a very important role.It is mainly responsible for the communication between the console and the drone.Two-way data transmission.Due to the flexible and variable position of the drone,and often flying at low altitudes in complex environments such as jungles or buildings,the channel characteristics are very complex,causing great interference to the communication between the drone and the console.The wireless channel simulator does not simulate its channel characteristics very well.Therefore,designing a wireless channel simulator that can accurately simulate the UAV channel is very valuable.In view of the above problems,this paper improves on the traditional Jakes channel model,optimizes the statistical characteristics of the original channel model,reduces the complexity of the algorithm and reduces the overhead of resources.At the same time,it proposes to adopt the mixed mode to generate Gaussian white noise.The method greatly improves the quality of Gaussian white noise.On this basis,the Nakagami-Lognormal composite fading channel model based on Gaussian variable decomposition is implemented and the design of composite fading channel simulator is completed.This article mainly studies the following parts:1.Analyze the applicable range and parameters of the existing wireless channel simulator and its advantages and disadvantages.According to the characteristics of the communication channel of the UAV,after in-depth study of the wireless channel theory,a suitable wireless channel model is proposed to clarify the wireless.The design requirements of the channel simulator are related to the performance indicators.Starting from two aspects of hardware design and algorithm implementation,a complete design scheme is proposed.2.The common channel model is simulated and analyzed,and an improved model based on Jakes model is proposed.The first-order statistical characteristics and second-order statistical properties are verified,which is in good agreement with the ideal situation.Aiming at the problem that the correlation characteristics of fading data caused by single-mode Gaussian white noise is not ideal in the traditional channel simulator,this paper proposes a method of generating Gaussian white noise by using mixed mode,which effectively improves the correlation characteristics of fading data.And based on this,the relevant Nakagami-Lognormal model is simulated and verified.3 According to the performance index and design scheme of the composite fading channel simulator,the hardware circuit design of the digital signal processing platform of the composite fading channel simulator is completed.The SOC software and hardware collaborative development technology is utilized to fully utilize the chip resources,and the signal processing algorithms of the channel simulator core module are completed,including multipath delay module,Doppler frequency shift module,channel fading module,variable rate signal processing module,and more.The system signal generation module and the instruction interaction module are developed in multiple modules,and the software and hardware cooperative design greatly improves the performance and flexibility of the composite fading channel simulator.The composite fading channel simulator designed in this paper has been tested and shown that each module and system are working normally,which basically meets the design requirements of the wireless channel simulator.