The HF Fax System Based On Packet Radio Network

Short wave communication has been widely used in government, the military, meteorological department and business to transmit languages, writings, pictures, and data etc. It's important in military communication because it won't be destroyed easily. HF radio fax is one of the important parts in short wave communication. To develop the HF radio fax system is necessary in the military training, though there are some difficulties in technique.In this paper the HF radio fax system was discussed, it has brought about some economic benefit. At first, a proposal is put forward .The TCT-301A radio modem and three types of fax machines were used to develop the HF radio fax system. Secondly, the principle of the HF radio modem and its key technology are discussed; the performance index and a diagram of the software and hardware are given. Thirdly, the design and key technology of the fax interface are discussed; and a common fax adapter, which has the function of error control, is designed. Its hardware and software are also built up. Finally, a research has been done on the packet radio network, and its implementations are described. According to the characteristics of short wave, the error control technology of the short wave channel is studied, and a new adaptive HARQ scheme is proposed, so the effectiveness of the short wave communication system is improved. The implementation and the flow diagram are described in details, and the system property is analyzed. According to the result of its application in the military, we come to the conclusion that the HF radio fax system is practical.