Synthetic HF Environment.
Final rept. May 67-Jun 68,
COMMUNICATIONS AND SYSTEMS INC PARAMUS NJ
Pagination or Media Count:
The purpose of this program was to provide a laboratory instrument that would accurately reproduce most of the channel impairments encountered by HF communication systems using ground-ground and air-ground links. A novel approach to obtain the performance specified for the HF simulator was a high-speed random access core memory as a variable multiple-tapped delay line, with the phase and attenuation of each tap under the real-time control of a small stored-program digital computer. The equipment was designed to reproduce the fine-grain multipath and fading characteristics of the HF medium in a pseudorandom sequence that is precisely repeatable at the operators discretion. Except for an input level adjustment, all parameter adjustments are made in the form of keyboard entries, as part of an operator-machine dialog. The acceptance tests demonstrated that the simulator accurately reproduces the channel impairments encountered on HF communication systems. The instrument provides operator control of fade rate, additive noise, specular-to-Rayleigh ratio, multipath spread, median level, number of paths, and Doppler shift. Author
- Radiofrequency Wave Propagation
- Radio Communications