Analysis and modeling of multiple-input multiple-output (MIMO) radio channel based on outdoor measurements conducted at 2.5 GHz for fixed BWA applications

This paper summarizes our 2x2 Multiple-Input Multiple-Output (MIMO) fixed wireless outdoor propagation measurements at 2.48GHz conducted in the suburban residential areas of San Jose, California. We report on various channel characteristics such as path loss, Ricean K-factor, Cross-Polarization-Discrimination (XPD) and channel capacity. We present simple models for these characteristics, focusing on excess loss dependency and, derived from that, the variation with distance. Also, we introduce an idea for a generalized MIMO channel model based on these modeled channel characteristics and the correlation properties between them. Path loss results show that blockage due to buildings or foliage causes an excess loss of 35.45 dB compared to free space propagation at a distance of 1km. The narrowband K-factor distribution matches previously reported results. The XPD of the total received signal varies from –10 to 15dB at various locations. The K-factor and XPD were found to be very much dependent on excess loss due to blockage conditions at various distances.