Design and test of a HF MIMO system of transmission set up with compact antenna arrays

This paper proposes a MIMO 2×2 solution to increase the capacity of HF radio links through the ionospheric channel. A diversity in the transmitted polarizations replaces the classical space diversity and authorizes a compact set up in a context of decametric wavelengths. After a theoretical step of capacity estimation, an HF 2×2 MIMO system has been designed and tested on a 300 km long radio link. The data transfer rate reaches up to 24.09 kbps (in a 4.2 kHz bandwidth) with a good quality of service.