Modeling the Multipath Cross-Polarization Ratio for 5 to 80-GHz Radio Links

In this paper, we parameterize an excess loss-based multipath component (MPC) cross-polarization ratio (XPR) model in indoor and outdoor environments for above-5 GHz frequency bands. The results are based on 35 measurement campaigns in several frequency bands ranging from 5 to 80 GHz. A conventional XPR model of an MPC assuming a constant mean value fits our measurements very poorly and moreover overestimates the depolarization effect. Our measurements revealed a clear trend that the MPC XPR is inversely proportional to the excess loss in reference to the free-space path loss. The model is physically sound as a higher loss is attributed to more lossy interactions or to a greater number of interactions with objects, leading to a greater chance of depolarization. The measurements furthermore showed that the MPC XPR is not strongly frequency or environment dependent. In our MPC XPR model, an MPC with zero-dB excess loss has a mean XPR of 27 dB. The mean XPR decreases half-a-dB as the excess loss increases by every dB and the standard deviation around the mean is 7 dB. The model is applicable to existing channel models to reproduce realistic MPC XPRs for the above 5-GHz radio links.