Design And Implementation Of Touch Channel Simulator Based On FPGA

Satellite channel simulator can simulate the propagation characteristics of satellite communications, debugg communication and save research costs.At present,many satellite channel simulators have some problems in the parameter setting:some satellite channel simulator is difficult to adjust parameters; some use the host computer to set the parameters,through the host computer parameters need to connect the computer,which reduce it's adaptability.Aiming at the above problems,designed a kind of satellite channel simulator based on FPGA and can touch.FPGA as an algorithm to achieve and control unit,through the control of the touch screen to facilitate the realization of parameter settings.The main contents of this paper are as follows:(1) The satellite channel transmission characteristics of the simulation program is designed.Through the analysis of satellite channel transmission characteristics,probability distribution function and classical channel model, the simulation scheme of satellite channel transmission characteristic is designed.(2) The system of satellite channel simulator hardware is designed. According to the index,seleced the suitable chips.FPFA as the core of the hardware system designed.The hardware system include FPGA module, touch screen module,A/D conversion module,D/A conversion module and filter circuit.(3) The program of satellite channel simulator algorithm is designed.The algorithm include Doppler frequency shift,multipath delay and gain,Rayleigh distribution, Lognormal distribution and Gaussian white noise.To verify the correctness of the Rayleigh distribution, logarithmic positive distribution and Gaussian white nois,using the hist function of MATLAB to produce histgram.(4) Satellite channel simulator control program is designed.Mainly included Nios II soft-core design,?C/OS- ? configuration,UCGUI transplantation,and finally designed the UCGUI interface of this system.(5) Builded test platform and tested performance.The test platform mainly include signal generator and oscilloscope.The signal generator generate a waveform to the satellite channel simulator and then output it to the oscilloscope. Observed the time and frequency characteristics of the input and output signals to verify the correctness of doppler shift. Derived the oscilloscope data to produce a histogram to verify the correctness of Rayleigh distribution, Lognormal distribution and Gaussian white noise.The system test results show that the designed channel simulator system can realize the simulation of satellite channel transmission characteristics and meet the design requirements.