Efficient propagation modelling for open-confined mixed space using a hybrid ray-tracing/waveguide theory method

The accurate prediction of radio wave propagation along highways plays an important role in the design of high-speed highway communication systems. The open-confined mixed space is a connection zone between the open space and confined tunnel along the highway. A hybrid propagation model is presented based on ray-tracing (RT) and waveguide theory, for the efficient modelling of open-confined mixed space. The proposed model employs RT to predict radio waves emitted by sources with arbitrary radiation patterns in open space sections, and utilises the waveguide theory approach to accelerate the prediction process in the confined tunnel sections. Both two-ray and six-ray RT models are included to take into account the suburban and urban environments. Numerical results are compared with simulated results generated by RT as well as experimental measurements. The validity and usefulness of the proposed model are demonstrated in an actual open-confined mixed space environment.