Nearest object priority based integrated rough surface scattering algorithm for 3D indoor propagation prediction

Since rough surface scattering has a great impact on the accuracy of the propagation prediction algorithm, an integrated algorithm for indoor propagation prediction including rough surface scattering is proposed here. This algorithm is composed of a three dimensional (3D) ray tracing algorithm based on binary space partitioning (BSP) and a diffuse scattering algorithm based on Oren-Nayar´s theory. Lack of accuracy and prohibitive time consumption are the main drawbacks of the existing ray tracing based propagation prediction models. To defy these shortcomings, the balanced BSP tree is used in the proposed algorithm to accelerate the ray tracing, while the nearest object priority technique (NOP) and in contact surface (ICS) is used to eliminate the repeated ray-object intersection tests. Therefore, the final criteria of this study are the time consumption as well as accuracy by predicting the field strength and the number of received signals. Using the proposed approaches, our algorithm becomes faster and more accurate than the existing algorithms. A detailed comparative study with existing algorithms shows that the proposed algorithm has at most 37.83% higher accuracy and 34.44% lower time consumption. Moreover, effects of NOP and ICS techniques and scattering factor on time and ray prediction accuracy are also presented.