The Design And Implementation Of A DSP-based HF Channel Simulator

The HF ionosphere reflection channel is one typical kind of time-varying and dispersive channel, and it has great theoretical significance to simulate the signal with the propagation characteristics of the HF channel, which is also supposed to have much practicability. In this paper, a DSP-based HF channel simulator within audio bandwidth is designed and implemented based on the concerned theory on the effects caused by the ionosphere in radio wave. Adopting Watterson Gaussian-scatter HF ionospheric channel model, the algorithms of simulation is performed by software programming. All system parameters are set from a control panel with LCD screen, the real-time digital processing of simulation is implemented with a DSP board based on TMS320VC33. Testing results show that this type of simulator is able to simulate the signal transferred in real ionosphere reflection channel restricted to narrowband providing with the main characteristics of multipath propagation, Rayleigh fading, Doppler shift etc, which means the simulator has reached the design requirements, furthermore, it can be performed with low cost and easy operation comparing with other congeneric products.