Reflection coefficient modification for mobile path loss calculation

In this paper we modify the reflection coefficient of electromagnetic wave incident on the wall of the buildings and obstacles that occurs in mobile communication path by solving the nonlinear Riccati equation. For this propose, the building walls are assumed to be inhomogeneous layers of bricks and limestone where their permittivity change as a function of the wall thickness. After modifying the reflection coefficient, a new propagation model based on UTD and GTD (uniform geometrical theory of diffraction and geometrical theory of diffraction) for multiple diffraction paths in cellular mobile radio communication is proposed and the diffraction loss as well as the path loss for a row of buildings with two inhomogeneous faces are calculated. Measured reflection coefficient and diffraction loss are compared to the theoretical results obtained in this paper for reflection coefficient and diffraction loss. Comparison of theoretical results and measured cases reveal that the modified reflection coefficient can adequately predict the reflective properties of the brick and limestone wall surface. Also the proposed UTD model results are in a good agreement with measured data. Therefore the modified reflection coefficient as well as the new UTD model can directly be applied to the estimation of multipath signal strength, diffraction loss and also path delay calculation in ray tracing algorithms used in mobile communication, radar and radio links