Realization Method Of ITS HF Channel Model On SDR Platform

Wireless communication technology has become an indispensable communication modein daily life. Being equipped with strengths like long communication distance, simpleequipment, invulnerability and low price, shortwave communication is now one of the maintechnique measures in the international communication service.A test for shortwavecommunication devices’ performance is requested in the process of developing such devices.It is absolutely necessary to simulate shortwave channel in laboratory environment, whichaugmenting the demand of shortwave channel simulators. Currently,the demand for datacommunication tends to be high-speed, large-capacity,and the traditional narrowbandshortwave channel simulator can not meet the requirements. Therefore, this article conductsproject, which bases on ITS model design and utilizes FPGA as signal processing core, torealize a wideband HF channel simulator.Firstly,this paper introduces the propagation characteristic of shortwave communicationin detail, after which it puts emphasis on the Watterson model and ITS wideband model of HFchannel in theory, then the two models are compared and analyzed and a new delay powerdistribution function,which is suitable for simulation and implementation,is propsed.Moreover,theoretically,this paper analyzes several influencing factors on HF channel, such as multipath,Doppler Shift and Doppler spread,as well as frequency selective fading. It sets a TDLsimulation model based on the study of tapped delay structure and analyzes theimplementation ability of HF channel simulator based on ITS model. At last, the ITS model isadopted as a theory model, based on which, the FPGA programme frame and main algorithmmodule was designed.Stimulation analysis is needed for all the projects.Finally,the design adopts the SDR hardware platform with Spectra OE which compliancewith SCA specifications version2.2.2realized the design of HF channel simulator.Tests inmultipath delay,Doppler Shift,Doppler Spread and amplitude fading are taken according to thepreceding design. The outcome certifies the design,which achieves request of the5msdelay,100Hz Doppler Shift,100Hz Doppler Spread.