Measurement of diversity gain and capacity on a MIMO-OFDM channel comparing different types of antennas

In the last decade, Multiple-Input Multiple-Output (MIMO) systems have created a great interest in research. Many works shows an increase in terms of data bit rate by using several antennas at each side of the radio link. In this paper, a novel measurement campaign of a MIMO channels in indoor environment is presented, in order to study the propagation characteristics of these systems so using both polarization and spatial diversity in multi-antenna systems can be evaluated, thanks to the use of three different types of antennas. A new MIMO-OFDM testbed (UMATRIX), designed and implemented in the UPM, has been used to accomplish the measurements. Capacity and diversity gain are studied, focusing on the importance of the channel normalization and comparing single and dual-polarized antennas. Moreover, an indoor-indoor laboratory and office environment has been considered to take into account the antenna effects at 2.45 GHz.