Accuracy improvement of ray-launching approach for indoor wave propagation through high lossy walls

This paper focuses on the transmitted wave through an indoor wall, which is composed by high lossy dielectric material. According to the Snell´s law, refracted propagation (real) angle thetas_t may be extended to a complex angle thetascirc_t for such lossy dielectric case. Especially, if the lossy effect of the wall material is large, Jfrm{thetascirc_t} may not be negligible small. In the ray-launching procedure, the complex angle thetascirc_t must be replaced with real shooting angle thetas_t, when one needs to calculate the transmitted ray through the wall. However, it is not clear how one determines the appropriate real shooting direction thetas_t inside the wall when the refracted angle becomes complex. In order to clarify the above question, this paper considers how to determine the appropriate real refracted angle thetas_t, by comparing the numerical ray-launching solution with the analytically derived reference solution. Accuracy improvement for higher lossy material cases is also discussed. Here time harmonic factor e^-iwt is assumed and suppressed throughout the context