Indoor path loss modeling for fifth generation applications

Abstract

The demand for high data rate transmission for the future wireless communication technology is increasing rapidly. Due to the congestion in the current bands for cellular network, it may not be able to satisfy the user requirements. For the future cellular networks, the millimeter wave (mm-wave) bands are the promising candidate bands because of the large available bandwidth. The 28 GHz and 38 GHz bands are the strongest candidate for fifth generation (5G) cellular networks. The channel needs to be characterized based on large-scale characterization to know the channel behavior in mm-wave bands in indoor environment. The narrowband channel is characterized based on the path loss model. For the development of new 5G systems to operate in bands up to 100 GHz, there is a need for accurate radio propagation models, which are not addressed by existing channel models developed for bands below 6 GHz. This attempt was conducted through extensive measurement campaigns and by using Information and Communication Solutions (ICS) Telecom simulation tool. The measurement environments were a closed-plan scenario in two buildings that included a line-of-sight (LOS) and non-line-of-sight (NLOS) corridor, a hallway, a cubicle room, and different adjacent-rooms communication links. The main limitation of the study was the limited distance range of LOS and NLOS environments because of the building structure design. Well-known single-frequency and multi-frequency directional and omnidirectional large-scale path loss models such as close-in free space reference (CI), floating intercept (FI) and alpha-beta-gamma (ABG) models and modified model are presented in this thesis. The modified model has a correction factor for different environments and it provides physically-based and efficient estimated path loss data points for the reference distance. Directional path loss model was done in co-polarized and cross-polarized antenna orientations, while omnidirectional path loss model was done in co-polarized antenna orientation only. The ICS Telecom simulation results show very high compatibility when compared with measurement campaign results. Also, it is found that the CI model is simpler, more convenient and more accurate for path loss prediction comparing with FI and ABG models. Also, the results show that the modified large-scale path loss model has the smallest path loss exponent (PLE), n and standard deviation, s values compared to the CI model. The results suggest that the modified path loss model can provide a sound estimation of path loss prediction and act as a reference analysis for developing mm-wave for wireless communication planning in indoor environments.