The MIMO cube - a compact MIMO antenna

Abstract

A compact MIMO antenna is suggested by combining polarization diversity and space diversity into one arrangement consisting of a cube where all 12 edges consist of an electrical dipole. The antenna should be useful in an indoor environment with waves arriving from many directions with arbitrary polarizations. The highest gain values are around 8.5 dB per cube and the theoretical capacity is 47 b/s/Hz for a basic SNR of 20 dB. The number of active channels is 12 for a side length of half-a-wavelength, but reduces to 6 for a very compact antenna. Even for less ideal conditions like only horizontal propagation, or lack of cross polarization, the capacity attains considerable values.