Deflecting-Obstacle Effects on Signal Propagation in the 60 GHz Band

This paper reports the non-line-of-sight (NLOS) results of broadband measurements and modeling of signal propagation characteristics in the 60 GHz band. The purpose of this work was to evaluate the importance of the presence of deflecting obstacles (DOs) for indoor wireless local area network (WLAN) applications in the unlicensed 60 GHz band. Based on sweeping-frequency sounding technique (59.6-60.6 GHz), an indoor propagation measurement campaign was carried out in a typical T-shaped intersection of two long corridors under non-line-of-sight (NLOS) at a distance of 20 meters between transmit and receive antennas, with and without the presence of DOs. Based on Ray-Tracing (RT) technique, deterministic models are derived for the considered environment. An interesting agreement is achieved between the predicted and the experimental results in both frequency and time domains. Thus, this work demonstrates that mm-waves communications are very sensitive to the propagation environment as compared with lower frequency bands. In NLOS corridor environments, the signal transmission relies mainly on the unavoidable diffraction phenomenon from the intersection corners. However, the presence of a DO might overcome significantly the hostile propagation characteristics that are normally encountered under NLOS propagation conditions.