Delay profile in quasi-millimeter band for fixed wireless access in urban area

This paper describes the estimated delay profile in the quasi-millimeter band for a fixed wireless access system considering a statistical model of buildings in an urban area. The signal scattered by the buildings is estimated by the GTD method. Assuming random location of the buildings makes the estimation extremely complex: numerical integration corresponding to the Huygens-Fresnel principle is improved to reduce computation time. The shadowing effect of the buildings is considered for both of two paths between the reflection point, and the antennas of the base-station and subscriber. This effect is estimated as the possibility to receive the scattered signal under the condition that there is a line-of-sight path between the two antennas. The calculated delay profile has a bump in the region with short delay in addition to a Rayleigh distribution. Similar delay profiles are obtained for various business regions in Tokyo. The reflected signal is lower than the line-of-sight signal by about 50 dB when the distance between the base-station and subscriber is about 1 km. The results suggest that good channel conditions are obtained for a short distance line-of-sight communication system.