[en] Polarization shift keying (PolSK) is a digital modulation technique using the state of polarization of an electromagnetic wave as the signalling quantity. PolSK comes from fibre communications, where the channel offers two orthogonal states of polarization. This article develops on the idea to adapt this technology to satellite communications, where similar channel conditions exist. For this purpose, a digital PolSK modem was implemented on a programmable logic board. A proposal for constellation design as well as thoughts on synchronization of PolSK over satellite is presented. The modem was used to demonstrate a 16-state Polarization Shift Keying link over a commercial satellite in Ku band. Measurements have been conducted in a back-to-back setup on intermediate frequency and on a Ku band transponder simulator to assess the impact of path-length differences, carrier recovery and non-linearity.
[Université du Luxembourg, and SES S.A., Betzdorf, Luxembourg]
