Deterministic Modeling of Indoor Stairwells Propagation Channel

A deterministic approach is presented for modeling a wireless propagation channel in a stairwell environment. The ray-tracing method is used to find the reflected and diffracted rays with the highest contribution to the total received power at a given location. Most significant reflected rays occur at the surfaces of specific steps of the stairwell and the surrounding lateral walls, while most significant diffracted beams emanate from the edges of steps located between transmitter and receiver antennas. The uniform theory of diffraction is used to calculate the diffracted contributions from the edges, whereas the multiple diffractions are calculated using heuristic diffraction coefficients. Unlike the reported models, the proposed model is deterministic and focuses on the radio propagation within stairwells at the X-band frequencies range. Experimental validation is performed using two types of antennas, horns and patches, for an operating frequency of 10 GHz. Simulated results of narrowband and wideband radio channels showed a good agreement with the experimental ones. The correlation coefficient between measured and simulation results is around 80% on average, and the residual errors between measured and simulated total received power results are less than 13%, which means that the proposed model has fair accuracy for such complex environments.