Propagation characteristics and modeling in indoor multi-floor environment

In this paper, the wideband propagation characteristic for an indoor multi-floor scenario is investigated based on wideband multi-frequency channel measurements in two typical indoor environments. Based on the measurement results, the log-distance (LD) model is used to analyze path loss (PL) in different floors. We find that the total penetration loss does not increase linearly in dB with the number of floors traversed, and the propagation condition in same floor, that is line of sight (LOS) or non-LOS (NLOS), can affect the penetration loss significantly. Besides, additional loss caused by traversing floor upwards is 1–2 dB larger than that introduced by traversing floor downwards. Then, we adopt a small error-prediction attenuation factor (AF) model for PL prediction. The modeling process and rationality of the AF model are presented. Finally, delay spread of wideband indoor channel is analyzed. Statistics of time dispersion parameters are compared among floors and frequencies. It is found that the delay spread on the middle floors is the largest, the delay spread on higher floors is relatively small due to lack of power source, and its relation with frequency is not obvious.