Fast Two-Dimensional Diffraction Modelling for Mobile Radio Propagation Prediction in Urban Micro-Cellular Environments

The paper presents fast two-dimensional (2-D) diffraction modelling in the horizontal plane for site-specific propagation prediction in urban micro-cellular environments. Comparison with measurements and simulation of published results validate the 2-D modelling that significantly reduces the computation time and overcomes the limitation and difficulty of existing techniques for multiple building diffraction. The modelling makes three contributions which are 1) extension of an expression for multiple building forward diffraction and use of the extended formulation, 2) equivalent source technique for parallel-street multiple diffraction and 3) inclusion of reflections from curved surfaces of street building corners. Additional comparisons of three-dimensional model prediction with measurements for an urban line-of-sight environment place the work in a more complete context The results show that an increase in the number of rays may not enhance the accuracy of ray-tracing model prediction.