New Communication System for Information Exchange in the Maritime HF Frequency Band

Nowadays, HF radio telex use on ships to contact terrestrial communication for data exchange between ships and coastal radio station. We need to exchange data between ships and users in control station for maritime search and rescue. Satellite communication systems use to exchange of large amounts of data with high transmission rates , but the problem of this system is high costs of equipment and services. We need to use simpler and cheaper technologies for data exchange to replace radio telex system. The aim of this paper, to study both systems, we could easily replace the maritime NBDP (Narrow Band Direct Printing) telegraphy.One system is based on OFDM (Orthogonal Frequency Division Multiplex) protocol, the other one use the PACTOR - III protocol. We compare details of two systems parameters such as the modulation method and data rate. They can select optimal data exchange system according to the specific features of maritime communications

کلیدواژه ها:

PACTOR ، protocol ، OFDM ، HF frequency