We consider antenna arrays equipped with cross-polarized antenna elements. The multipath propagation will affect both the spatial characteristics and the polarization of the received signals which will influence the performance of the system in terms of, for example, bit error rate or direction estimation. In this paper, we present results from field measurement data recorded at the 1800 MHz band, provided by Ericsson Radio Systems AB. The study is divided into two main parts. In the first part we introduce a diversity gain measure related to the BER of an MRC receiver. The polarization diversity introduced by the radio channel is studied, and compared to the spatial diversity. In the second part we use a parameterized model of the received polarized radio waves and illustrate the typical behavior of the estimated polarization parameters