Polarisation characteristics of propagation paths in indoor 70 GHz channels

This document presents cross-polarisation ratios (XPRs) of propagation paths measured in indoor 70 GHz channels. To the best of authors' knowledge, very few polarisation measurement results of millimetre wave channels have been reported. The channel measurements are performed in large indoor short-range scenarios such as offices, a shopping mall, and a railway station. Due to the large measurement bandwidth of 5 GHz and the high cross-polarisation discrimination of the antennas, which is more than 25 dB, we are able to identify the XPRs of the individual propagation paths reliably. In total 36 paths have detectable cross-polarisation components above the noise floor. A range of the XPRs between 10 - 30 dB is observed. More polarisation measurements are needed for meaningful statistical analysis of the path XPR.