Wideband impulse response of indoor channel at 2 GHz using directive patch antennae

Abstract

Wideband impulse measurements using a vector network analyser at 1.95 GHz have been made in a typical laboratory setting. Directive patch antennae were placed at 2 m and 1.5 m heights. The median root mean square (RMS) delay spread found is 8 ns for an antenna height of 2 m and 11 ns for a 1.5 m height in line-of-sight (LOS) areas. In obstructed (OBS) areas, a delay of about 25 ns is obtained regardless of the antenna heights. There is a correlation between the RMS delay spread and the transmit-receive (T-R) distance in LOS areas; but it is independent in OBS areas. The average path loss in LOS is a function of the distance and the antenna heights. Moreover, there is a high correlation between the RMS delay spread and the average path loss. The results presented advocate the use of directive antennae with a careful selection of antenna height and positions for a high speed wireless local area network.