Improved Ray-Tracing for advanced radio propagation channel modeling

The characterization of the wireless propagation channel has always been an important issue in radio communications. However, in recent years, given the dramatic increase of demand in terms of capabilities of wireless systems, e.g. data rate, quality of service etc., the study of propagation has become of crucial importance. As measurements are generally costly and time consuming, channel models are widely used for this purpose. The modeling of propagation may rely on different types of models: empirical, statistical and deterministic. Typically, the latter, based on the electromagnetic properties of the propagating waves, relies on Ray-Tracing (RT), a geometrical optic technique used to evaluate the paths followed by rays as they interact with the environment. This technique has been widely used to predict the behavior of propagation both in outdoor and indoor scenarios. Classic RT tools take into account line of sight propagation, specular reflection and diffraction, with penetration included when indoor propagation is considered. With the advent of diversity techniques and MIMO systems, whose goal is to exploit the multi-dimensional properties of a channel, it is required that the prediction models are capable to analyze propagation in depth, i.e. including polarization, delay and angular behavior of a channel. A 3-D RT tool has the great advantage to be able to provide inherently that kind of information, but to achieve a sufficient accuracy, it is necessary to develop an advanced prediction tool. To this goal, a pre-existent RT tool has been improved by implementing in it propagation mechanisms as penetration, diffuse scattering and contributions by vegetation.
(FSA 3) -- UCL, 2012