The Study of Beyond Line-Of-Sight Indoor Propagation Channels and Diversity Techniques

In this paper, we use a novel ray tracing technique to study indoor propagation channels and diversity systems in the millimetre wave band. This technique is used for the first time to study diversity techniques in non line-of-sight environments. The selected area has an L-shaped corridor and an adjacent room. The CPD's (Cumulative Probability Distribution) of the centre line of the corridor and the room are calculated showing almost Rayleigh and Rician distribution respectively. The rms delay spread in the corridor is found to be more than that for the room. The influence of carrier frequency on CPD and rms delay spreads is also investigated. Frequency, space and polarization diversity are investigated and diversity gains are calculated for different frequency separation and different antenna separation. We also compare the results of using the diversity scheme with omnidirectional transmitter antenna and the case of no diversity with a transmitter dipole antenna. The results show that the performance of the diversity scheme is better than using of a dipole antenna in the transmitter in the non line-of-sight area.