  In this paper we present a novel modulation technique for dual polarization
communication systems, which reduces the error rate compared with the existent
schemes. This modulation places the symbols in a 3D constellation, rather than
the classic approach of 2D. Adjusting the phase of these symbols depending on
the information bits, we are able to increase the bit rate. Hence, the proposed
scheme conveys information by selecting both polarization state and the phase
of radiated electromagnetic wave. We also analyse the performance of 3D
Polarized Modulation (PMod) for different constellation sizes and we obtain a
curve of rate adaptation. Finally, we compare the proposed 3D PMod with other
existing schemes such as single polarization Phase Shift Keying (PSK) and
double polarization Vertical Bell Laboratories Layer Space-Time (V-BLAST), both
carrying the same number of information bits. The results show that 3D PMod
always outperforms all other schemes, except for low order modulation.
Therefore, we can conclude that 3D PMod is an excellent candidate for medium
and high modulation order transmissions.
