An Adaptive Automatic HF Radio.

This report describes the preliminary design of an automatic adaptive HF radio network for use in a post-nuclear environment. The radio features a multipath-resistive signaling waveform and a linking protocol that will enable an inexperienced operator to establish contact with any station in its network, provided that propagation support between the two stations exists. If propagation support does not exist on any of the assigned channels, the radio will continually cycle through all of its assigned channels until contact is established, or until the attempt is aborted. Thus, contact will be made as soon as propagation conditions permit. An adaptive radio system of the type described here will provide significant improvement over conventional HF communication systems in its linking protocol and its ability to adapt to changing propagation conditions. The radio is expected to be low in cost and highly portable so that it can be proliferated easily to provide emergency communications between users. The radio is not intended to be used for extended exchanges nor to be competitive with the sophisticated systems currently being considered for MEECN applications in the extremely hostile propagation and jamming environment that follows immediately after a nuclear attack.