The Simulation And Implementation Of A DSP-baesd Narrowband HF Channel Simulator With Watterson Model

HF communication plays an important role in middle or long distance wireless communication all the time. HF channel is a rapid time variation and dispersion channel. It has three selective fading of time,frequency,space. These fading seem to be the most serious distortion factor that degrades the communication performance over HF channel. Then, HF channel's characteristic is the focus that people research the HF communication.Usually, people need test the performance of the HF communication equipment in the HF communication engineering. It takes much time and resources, and it is impossible having the same tested condition. Along with the development of hardware's operation speed and the HF communication's non-replace in troops, this kind of test method can't meet the demands obviously. In this case, design a kind of equipments which can imitate a condition of various HF channel is necessary.Based on actual engineering and the theory of the ionosphere in radio wave, we determine the basic implementation of the program, combined with modern digital signal processing. Through this simulator, people can change the HF channel parameters such as Multipath Delay,Doppler frequence offset,Doppler frequence spread. After research the Watterson system model, a audio bandwidth HF channel simulator which is DSP-based is designed. Adopting Watterson Gaussian-scatter HF ionospheric channel model, the algorithms of simulation is performed by software programming. The digital processing of simulation is implemented whit a DSP board based on Texas Instruments Inc's TMS320C6713 chip. Finally, in order to verify the feasibility of the program,contrast the output wave with the emulator result which is calculate from Matlab. After contrast two waves, the result indicate that this HF channel simulator has reached the design requirement.