Towards Efficient Spectrum Utilization with Polarization-Based Architectures

2. Mimo System Architectures

The specific polarization-based MIMO architectures considered in our work includes dual-polarization MIMO (DP-MIMO) architectures and space-polarization MIMO (SP-MIMO) architectures. As shown in Figure 1, DP-MIMO architectures incorporate orthogonally-polarized elements that share a common phase center at each transceiver, leading to a 2X2 MIMO configuration. The DP-MIMO architecture can be expanded to incorporate additional space channels, for example to yield a 4X4 SP-MIMO system, as shown in Figure 2. In this case there are 16 individual paths (and 256 correlations) that help to characterize the MIMO channel.

Figure 1.

Dual-polarized MIMO system

Figure 2.

Space-polarized MIMO system

Polarization-based MIMO architectures offer certain advantages relative to more conventional co-polarized arrays. First, in space-constrained applications, one strategy for increasing system capacity is to employ a dual-polarized antenna at each antenna location.