Efficient ray-tracing techniques for three-dimensional analyses of propagation in mobile communications: application to picocell and microcell scenarios

Abstract

The application of se:veral ray-tracing techniques, in combination with GTDKJTD (Geometrical Theory of Diffraction/Uniform Theory of Diffraction), for an efficient analysis of propagation in urban scenarios is presented. The frequency of the analysis is in the UHF band, and a three-dimensional model of the geometry, using flat facets, is considered. After a review of the most commonly used ray-tracing techniques, a new method, called the Angular Z-Buffer (AZ13) technique, is presented. As is shown and validated with results, the AZB appears to be extremely efficient for GTDKJTD applications.

High Frequency Techniques: the Physical Optics Approximation and the Modified Equivalent Current Approximation (MECA)

“…As a consequence, a preliminary discrimination is accomplished by blocks, so the facets are discarded faster. In this category, the Angular Zbuffer (AZB) (Cátedra et al, 1998) or the Space Volumetric Partitioning (SVP) (Cátedra & Arriaga, 1999) is included. Additional acceleration can be achieved when the same algorithms are developed in Graphic Processing Units (GPUs) instead of Central Process Units (CPUs) (Ricks & Kuhlen, 2010).…”

Arbitrary Voxel Selection for Accelerating a Ray Tracing-Based Field Prediction Model in Urban Environments

“…The time required by the RT algorithm to compute all rays connecting T x s and R x s exponentially rises as the number of facets linearly increases [1]. Therefore the physical coherence of the deterministic approach leads to a boost of the computational time and this propagation model is thus often considered time expensive if compared to the empirical and statistical ones.…”

“…They split the space seen from a point in angular or axis-aligned regions and store the facets of the model in the regions where they belong. For example, Angular ZBuffer (AZB), Space Volumetric Partitioning (SVP), Occluder Fusion, and Binary Space Partitioning (BSP), have received great attention [1][2][3]. Because they act only by speeding up geometrical checks, they do not introduce any approximation in the field prediction compared with the full 3D RT analysis.…”

Efficient Radio Propagation Prediction Algorithm Including Rough Surface Scattering With Improved Time Complexity

“…Hence, if all objects participate in this test, the ray tracing time consumed will be extremely high. To accelerate the ray tracing technique, various methods such as angular sectoring [8], KD-tree, octree, quad tree [4] and a preprocessing method are proposed [7]. However, the existing models, such as shooting and bouncing ray (SBR) [4], bidirectional path tracing (BDPT) [9], brick tracing (BT) [10], ray frustums (RF) [11], prior distance measure (PDM) [7], and space division (SD) [12] techniques require higher prediction time due to complex algorithms used.…”