A comparison and verification of 2D and 3D ray tracing propagation. Models for land mobile satellite communications

Propagation modeling for land mobile satellite (LMS) systems is mainly used for system design. Questions of interest include the design of error protection, equalization, synchronization, Doppler compensation, as well as the performance evaluation of power control, satellite or polarization diversity, and handover. Therefore typical wideband time series are required, that include shadowing, short term fading, echo delay, Doppler, and polarization effects. Ray optical propagation models offer an excellent means to perform such in-depth propagation studies. In the following a two-dimensional (2D) and a three-dimensional (3D) ray tracing model for non-urban areas are briefly outlined. The performance of the two models is evaluated using LMS measurements. It is shown that 3D propagation modeling considerably increases prediction accuracy of first and second order channel statistics.