Polarization measurements and modeling in indoor NLOS environments

Cross-polarized antenna systems are an attractive way to reduce equipment size while maintaining low interantenna correlation. In this paper, the polarization behaviour of indoor channels is investigated. A measurement campaign has been conducted at 3.6 GHz for a dual-polarized transmitter and a tri-polarized receiver in a non-Line-of-Sight (NLOS) scenario. The spatial and delay characteristics are extracted using a pertap beamforming algorithm. Distinct paths are isolated and the polarization of each wave is expressed in terms of its spherical components. The cross-polarization discrimination (XPD) of the wave is investigated as a function of its physical propagation parameters. The XPD of the wave is shown to be sensitive to spatial characteristics, while being insensitive to delay.