Spatio-temporal channel characteristics at 5 GHz in a typical office environment

In order to assess important direction-delay indoor propagation characteristics, a combined wideband and 3D spatial channel measurement campaign has been performed in the frequency band 5.1-5.3 GHz (HIPERLAN type 2 band) in a modern office building. Non- line-of-sight (NLOS) measurements in a corridor environment on a single floor and measurements between floors were performed. Joint determination of direction of arrival and distance was obtained by means of maximum likelihood (ML) estimation of the radio channel. The main pathways between the transmitter and receiver were identified from the point source estimates and reconstructed in structural drawings of the building. From the results it can be concluded that both geometrical optics (GO) and diffraction (scattering) are important propagation mechanisms in NLOS indoor scenarios. The cross-floor results show a strong attenuation of the direct wave (25 dB per floor). The total path loss is, however, reduced due to reflection paths from an adjacent building.