Measurement Results for the Comparison of Multiple and Single Polarized MIMO Channels in LOS, NLOS, Indoor and Outdoor Scenarios

Abstract:
This paper presents measurement results at 2.3 GHz for multiple-input multiple-output (MIMO) systems applying multiple polarized antenna arrays and single polarized uniform linear arrays (ULAs). The measurements were taken indoor in two different buildings, outdoor between a base station on the rooftop and a mobile station in a car, as well as between two mobile stations in two cars (C2C). Measured values for the channel pathloss, the cross-polarization discrimination (XPD), the co-polarization power ratio (CPR) and the normalized channel capacity or bandwidth efficiency of many different scenarios are presented. Systems with two co-polarized, co-located antenna elements (Cross) at both link ends and systems with three perpendicularly polarized, co-located antenna elements (Tripod) are further investigated and compared to the corresponding ULA with varying inter-array antenna distance. It figures out that 2x2 MIMO systems with Cross antennas outperform single polarized ones with respect to the achievable bandwidth efficiency in LOS environments with few multipath components. In most other cases, the ULAs performs better than the Cross or the Tripod, due to the larger amount of received power.