Analysis of millimetre-wave polarization diverse multiple-input multiple-output capacity

Abstract

Millimetre-waves offer the possibility of wide bandwidth and consequently high data rate for wireless communications. For both uni- and dual-polarized systems, signals sent over a link may suffer severe degradation due to antenna misalignment. Orientation robustness may be enhanced by the use of mutual orthogonality in three dimensions. Multiple-input multiple-output polarization diversity offers a way of improving signal reception without the limitations associated with spatial diversity. Scattering effects often assist propagation through multipath. However, high path loss at millimetre-wave frequencies may limit any reception enhancement through scattering. We show that the inclusion of a third orthogonal dipole provides orientation robustness in this setting, as well as in a rich scattering environment, by means of a Rician fading channel model covering all orientations for a millimetre-wave, tri-orthogonal, half-wave dipole transmitter and receiver employing polarization diversity. Our simulation extends the analysis into three dimensions, fully exploiting individual sub-channel paths. In both the presence and absence of multipath effects, capacity is observed to be higher than that of a dual-polarized system over the majority of a field of view.

Planar slot antenna with circular and vertical polarization diversity

“…Two commonly used criteria, the mean effective gain (MEG) and the envelope correlation coefficient (ECC), are utilized to evaluate the antenna diversity performance and are shown in Figure . Spherical integration functions of the 3D far‐field antenna patterns are used to calculate both MEG and ECC metrics using a diversity model . A lower MEG limit of −10 dBi and an ECC upper threshold of 0.5 are commonly held as acceptable for diversity applications.…”

Tri‐orthogonal polarization diversity reception for non‐geosynchronous satellite orbit ionospheric channels

“…We invoke the model used in [41] to provide analysis over antenna orientations at R within the FoV, according to orbital parameters. Faraday and path delay are calculated and included according to the work in [34].…”

Sixty Years of Coherent Versus Non-Coherent Tradeoffs and the Road From 5G to Wireless Futures

“…However, as the power is split between the pair, the employment of circular polarization requires an increased transmit power, which becomes a challengue to deliver in the mmWave band owing to the fact that the PA's dynamic range generally reduces upon increasing the frequency [58], [145]- [147]. Against this background, the state-of-the-art tri-orthogonal polarization technique that was originally proposed for achieving a diversity gain in rich-scattering microwave channels [148], [149] may be harnessed for the three-dimensional beamforming in the LoS-dominant mmWave channels [147], [150], [151]. More explicitly, it was demonstrated in [147], [151] that by using three polarized ports, at least two polarizations are always adequately aligned in any link direction.…”

“…Against this background, the state-of-the-art tri-orthogonal polarization technique that was originally proposed for achieving a diversity gain in rich-scattering microwave channels [148], [149] may be harnessed for the three-dimensional beamforming in the LoS-dominant mmWave channels [147], [150], [151]. More explicitly, it was demonstrated in [147], [151] that by using three polarized ports, at least two polarizations are always adequately aligned in any link direction. Nonetheless, the polarization diversity techniques suffer from the cross-polarization discrimination, which refers to the mean signal difference between co-polarized and cross-polarized branches [152].…”

“…Moreover, due to the insufficient isolation, the deleterious coupling of energy between polarized ports also leads to substantial capacity loss [149], [153]. For further discussions on these issues, interested readers might like to refer to [147], [151] for more details in this area.…”