The Impact of Vehicular Antenna Placement on Polarization Diversity

In this paper we describe a series of urban measurements designed to characterize the MIMO channel when antenna arrays with dual-polarized elements are placed on the sides of the mobile receiver. It is seen that the received signal power is highly dependent on the physical environment local to the receiver and on the position of the vehicular mounted array elements relative to the transmitter. These factors, combined with the channel´s propagation characteristics, result in a spatial power imbalance across the arrays as well as cross polarization discrimination (XPD). When the spatial array power imbalance (API) exceeds the XPD polarization diversity can be exploited to improve the system performance. However, when the XPD is greater than the API spatial diversity results in improved performance.