On Polarization and Frequency Dependence of Diffuse Indoor Propagation

The room electromagnetics (RE) theory describes the radio propagation in a single room assuming diffuse scattering. A main characteristic is the exponential power-delay profile (PDP) decaying with the so-called reverberation time (RT) parameter, depending only on the wall area, the volume of the room and an absorption coefficient. The PDP is independent on the location in the room, except for the arrival time. Based on measurements in a room with a spherical array of 16 dual- polarized wideband horn antennas, the current work studies how the RE parameters depend on the receiver (Rx) antenna polarization and orientation. Also the frequency dependence is investigated, with measurements done at both 2.3 GHz and 5.8 GHz center frequencies. The RE theory was found to fit well to the measurements with a RT in the range 22- 25 ns. Only small differences were found due to the polarization and the channel gain was depending approximately as expected with frequency.