SBR/image approach for radio wave propagation in furnished environments

Detailed understanding of the radio propagation characteristics in a room will help the design of personal communication services (PCS) systems. In this paper, a deterministic approach using a modified shooting-and-bouncing-ray (SBR) technique denoted as the SBR/image method is developed to deal with the radio wave propagation in furnished rooms, and the reception sphere is not needed. Conceptually we use the SBR method to trace ray tubes (not rays) bouncing in the room. If the receiving antenna (Rx) is within a ray tube, the ray tube will have contribution to the received field at Rx and the corresponding equivalent source (image) can be determined. In addition, the first order wedge diffraction from furniture is included, and the diffracted rays also can be attributed to the corresponding images. By summing all contributions of these images, we can obtain the total received field at Rx. Numerical experiments have been conducted to investigate the radio wave propagation in rooms with metallic furniture, because these kinds of furniture are the most dominant reflectors in furnished rooms. The results show that the diffraction effect can be neglected in such environments where multiple reflection is severe.