A 2D ray tracing model for indoor radio propagation at MM frequencies and the study of diversity techniques

Abstract

In this paper we describe a deterministic approach to model radio propagation channels in complex environments and use the model to study diversity techniques. In this model we divide the environment into a number of equal sized rectangular cells. Each cell can have its own permittivity and conductivity. The simulation is based on geometric optics and uses ray tracing techniques. The information needed to reconstruct the field strength pattern inside each cell, such as the angle of entry, distance from source and polarization of each ray, are calculated on the boundary of every cell. The effects of all rectangular obstacles, such as walls, doors, columns, and so on, are considered by the model. Both reflection and refraction effects are taken into account. The modelled results of Cumulative Probability Distribution (CPD) in a case of non line-of-sight and r.m.s. delay spread for the long corridor are presented. The performance of space, frequency and polarization diversity is also investigated by use of the model. The results show that space diversity is found better than polarization and frequency diversity in the environments examined.