Energy Efficiency of Space and Polarization MIMO Communications With Packet Erasures Over Wireless Fading Channels

摘要

The transmit energy efficiency (EE) of space–polarization multiple-input multiple-output (SpPol-MIMO) architectures, dual-polarized MIMO architectures (DP-MIMO), and conventional co-polarized MIMO (CP-MIMO) schemes are compared for packet-based communication systems using full multiplexing without channel state information at the transmitter. We develop a closed-form approximation for assessing the EE of single-input single-output (SISO) and MIMO systems and show tradeoffs that exist between EE, spectral efficiency, modulation schemes, and packet designs. Using a hardware/software testbed, we also compare the EE among SISO, 2 2 CP-MIMO, 2 2 DP-MIMO, and 4 4 SpPol-MIMO architectures in frequency-selective MIMO channels. Emulation results from the testbed indicate that in the high SNR-regime, SpPol-MIMO provides the best EE performance in spatially uncorrelated channels, with EEs approximately four and two times better than SISO and 2 2 MIMO architectures, respectively. In Rician channels exhibiting either partial or high spatial correlation, DP-MIMO offers more than a performance improvement relative to the other architectures at high SNR. At low SNR, SISO systems offer the best energy efficiency but also exhibit the lowest data rates. For all of the architectures, operating points are identified that provide near achievable data rates while operating at a local minimum in energy consumption.