Dual Polarized Spatial Modulation for Land Mobile Satellite Communications

In this paper, two novel high-rate multiple-input multiple-out (MIMO) transmission schemes are proposed for dual polarized land mobile satellite (LMS) communications, where the polarization dimension and spatial dimension are jointly exploited to convey information. To be specific, we first extend the concept of polarized modulation (PMod) from single antenna LMS systems to multi-antennas LMS systems, which utilizes the parallel polarization states for bit mapping. This new scheme, namely generalized PMod (GPMod), is capable of improving the transmission rate linearly with the number of transmit antennas. For high-rate scenarios, the proposed GPMod needs to deal with the interference introduced by cross polarization, which may degrade the system performance. In order to circumvent the cross-polarization interference, we employ the concept of index modulation to both polarization dimension and spatial dimension and proposed a novel interference-free scheme, namely polarized spatial modulation (PMod-SM). Finally, an upper bound for the average bit error probability (ABEP) of the proposed scheme is derived for the generalized spatially correlated Rician channel model. Both analytical and simulation results are presented to demonstrate that the proposed PMod-SM scheme is capable of achieving considerable performance gains compared to the conventional PMod and the GPMod schemes.