Energy Efficiency of Co-polarized and Space-Polarization MIMO Architectures in Packet-Based Communication Systems

In this paper, we study the energy efficiency of space-polarization MIMO (SP-MIMO) architectures as compared to conventional co-polarized MIMO (CP-MIMO) schemes in packet-based communication systems. In SP-MIMO architectures, co-located dual-polarized (DP) antennas are employed at each of the antenna locations, effectively doubling the number of ports without substantially increasing the footprint of antenna arrays. The energy efficiency of CP-MIMO architectures has been explored intensively in literature, however very few results are available for DP-MIMO and SP-MIMO systems, particularly over realistic and imperfect channels. We compare the energy efficiency among single input single output (SISO), CP-MIMO, DP-MIMO and SP-MIMO architectures over various wideband MIMO channels. The comparative performance studies are conducted on a SP-MIMO testbed, which incorporates baseband generators, MIMO channel emulation, a coherent multi-channel receiver, and a host computer for signal processing. Results from the testbed indicate that SP-MIMO offers a significant performance shift relative to SISO and CP-MIMO system, especially at high signal-to-noise-ratios. In this region of operation, SP-MIMO provides average transmit energies per successful received bit that are nearly four times and two times less than for SISO and for CP-MIMO architectures respectively.