Implementation of a MIMO solution for ionospheric HF (3-30 MHz) radio links
Résumé
MIMO architectures are generally based on antenna arrays with spatial diversity. An implementation in the particular context of trans horizon transmission through the ionospheric channel copes with the problem of prohibitive array aperture, the wavelength being decametric in the corresponding HF frequency band (3-30 MHz). Therefore, this paper proposes an alternative resorting to the diversity in transmitted polarizations. The design of an original 2x2 MIMO system is detailed and the experimentations carried out on a 280km long transmission are presented. The first results underline a data transfer rate reaching a value of 24.09 kbps (in a 4.2 kHz bandwidth) which significantly exceeds the current standards for HF modems. Keywords