Analysis of wideband propagation characteristics for the high transmission rate in indoor radio channels

In this paper, the wideband propagation characteristics were analyzed by the frequency sweeping method. In order to investigate the possibility of a high transmission rate in indoor radio channels, we adopted a circularly polarized antenna in the indoor field tests under line-of-sight (LOS) and non-line-of-sight (NLOS) environments. We analyzed the effects of both human motions and transmission antenna heights. From the indoor field tests, it was found that amplitude deviation within the frequency bandwidth should be improved by circularly polarized waves under LOS conditions, due to removing the reflected wave with an odd number. Also it has been found that there exists an improvement of the amplitude deviation with polarization diversity reception under an NLOS environment. In addition, for the case where the transmission antenna height is changed up to the ceiling height, it has been found that there should be improvement of the wideband amplitude deviation for the high speed transmission system, using polarization diversity.