Computer-controlled Shortwave Adaptive Communication Network

The short-wave telecommunication is based on the electromagnetic wave's reflection on the ionosphere. The ionosphere itself is time-varying because of some factors such as the macula, so the quality of short-wave channel is affected by multipath transmission , Doppler effect , elective attenuation and jamming. Normal short-wave telecommunication system does not make prevention and solution aiming at the above factors. It can not accomplish automatic selection of frequency and automatic link establishing. The application of short-wave telecommunication was restricted greatly.Following the appearance of adaptive short-wave system, the USA bring forward the federal standard FED-STD-1045. It factually is the standard of automatic link establishing(ALE). To make all the radios conforming this standard communicate each other, it formulates the wave pattern of ALE signals, the detection of channels, the rules of calling and service.Based on the radios conforming the FED-STD-1045, this paper brings forward a method to construct a computer-controlled adaptive short-wave telecommunication system. It will improve the efficiency of short-wave telecommunication nets on the following aspects: the frequency sharing, automatic link establishing, adaptive changing of baud rate and switching of channels.The system is constructed by central station and external station. The central station comprises one upper computer and three lower computer. Each lower computer connects to a radio and a receiver. The radio and the receiver will send commands to external stations and receive data from them. Each lower computer is in charge of two external stations. The external station comprises a computer, a receiver, a radio and relevant...