In this paper, we propose a deterministic approach to model the radio wave propagation channels in complex indoor environments. This technique applies the modified shooting-and-bouncing-ray (SBR) method to find the equivalent sources (images) for each launched ray tube. 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 the contributions of all these images coherently, we can obtain the total received field at a receiver. Besides, the vector-effective height (VEH) of an antenna is introduced to consider the polarization coupling effect resulting from multiple reflection inside the rooms. We verify this approach by comparing the numerical results in three canonical examples where closed-form solutions exist. The good agreement indicates that our method can provide a good approximation of high-frequency radio propagation inside rooms where multiple reflection is dominant. Work reported in this paper has shown that the propagation loss in indoor environments varies considerably according to furniture and polarizations.