Low-rate modem for transmission of small data in medium frequency range for Arctic

• Published in: Omsk Scientific Bulletin
• Main Authors: P. I. Puzyrev, S. A. Zavyalov, V. V. Erokhin, V. Yu. Shein
• Format: Article in Journal/Newspaper
• Language: English; Russian
• Published: Omsk State Technical University, Federal State Budgetary Educational Institution of Higher Education 2018
• Subjects: modem; multiple frequency shift keying; detector; Engineering (General). Civil engineering (General); TA1-2040; Arctic
• Online Access: https://doi.org/10.25206/1813-8225-2018-160-145-151; https://doaj.org/article/91f3634923d14b1c82c22d01014b78da

In this paper, we consider the implementation of a low-rate modem for the transmission of small data, such as short text messages, distress messages, commands, notifications, coordinates, etc. The modem uses orthogonal 64-position frequency shift keying characterized by a lower probability of bit error, the possibility of non-coherent demodulation and a constant envelope. The structure of the modem is designed for implementation in software and for the implementation in languages of the description of equipment for SDR systems. The procedure of primary time synchronization, detection, frame synchronization and demodulation is considered. The use of a low-rate modem will expand the radio coverage area in the Arctic, where there are no cellular networks.