Correlation bandwidth characteristics for paths between base station and building roofs

Correlation (coherence) bandwidths for the paths between base station and building roof antennas were obtained from the amplitude-frequency characteristics measured on the roofs of 11 buildings in Tokyo, Japan, in the 900-MHz band. For the cases where the base-station antenna was in the line-of-sight from the building roof antenna and the propagation loss was 2-9 dB larger than the free-space propagation loss, the correlation bandwidth decreased as the excess loss from free-space propagation loss increased. For out-of-sight cases, correlation bandwidths ranged from 38 to 320 kHz and were similar to those estimated for on road. The correlation bandwidth measured using a 12-element Yagi antenna was double that measured with a half-wave dipole antenna.