A Novel Projection-Based Beam Ray Launching Method for Wireless Channel Modeling

In this article, a 3-D projection-based beam ray launching (PB-RL) method is proposed for improving the efficiency of ray-tracing (RT) channel modeling. PB-RL utilizes the projection concept to define two types of ray beams for accelerating intersection tests and reception tests. With the help of projection, intersection tests between beams and walls are simplified to judgments between projected polygons, where an improved Gilber–Johnson–Keerthi (GJK) algorithm is applied to obtain accurate judgment results with reduced complexity. Based on the shapes of propagated beams, reception tests are accelerated by minimal box pre-judgments, which is especially effective for a vast array of receiver (Rx) points. Propagation of rays is completed by the transformation of ray beams, with a detailed illuminated area computed by clipping, generating sub-beams precisely for each covered object. Simulation results show that the total computational time is reduced significantly as compared with traditional RL methods. Channel characteristics computed by PB-RL are more accurate than those obtained by traditional methods, which are verified by measurement data.