  The use of dual polarization in mobile satellite systems is very promising
for increasing the channel capacity. Polarized Modulation is proposed in this
paper for use in practical systems, by providing simple equations for computing
its capacity and featuring a link adaptation algorithm. This scheme shows
remarkable gains in the spectral efficiency when compared with single
polarization and other multi-antenna techniques such as V-BLAST. Polarized
Modulation is a particular instance of more general Index Modulations, which
are being considered for 5G networks. Thus, the proposed link adaptation
algorithm could find synergies with current activities for future terrestrial
networks.
