A ray tracing approach to predicting indoor wireless transmission

Several models exist for the statistical characterization of microwave propagation within buildings. Statistical models do not provide site-specific information. A hybrid model is proposed, in which ray tracing is used to predict, at any given location, the local mean of the received power and the delay profile. Variations about the mean values can then be captured via a statistical description matched to the local environment. An efficient 3-D ray tracing algorithm is described which accounts for all (transmitted as well as reflected) rays reaching the receiver location after an arbitrary number of reflections. The effects of the angle of incidence, the material dielectric constant and the antenna patterns are included. The predicted values for the local means of the received power are then compared against measurements to establish the accuracy of this approach.