74 GHz), with tems or parts thereof such as antennas, specially taking into account obstacles: terrain (including forests), two, three or four elements. Here the main purpose was to compute the mean capacity of the MIMO channel. (complex) buildings and moving objects. Essentially three kinds of method will be discussed: Paper [NdHH04] develops an own MoM Galerkin solver and compares the results of a 40 piecewise linear (tri- 1. integral methods (moment methods, physical optics angular) basis functions for a half wavelength dipole with and modal expansion); 2. differential equation methods (Finite Difference Time Domain (FDTD) and parabolic equation); 3. ray methods (tracing/launching and Gaussian beams). 4.7.2.1 Integral methods This subsection deals with the most accurate methods Figure 4.7-1 Practical implementation of the dodecahedral available in electromagnetics to describe waves. antenna. Propagation modelling and channel characterisation CHAPTER 4.7 the classical sinusoidal distribution. The final goal is the more complex data of real terrains in both Denmark and same as in the previous two papers, namely determining Ireland. For those cases measured data was available. the capacity of a (2 X 2) MIMO system. The conclusions were that the copolar components did Moment methods have not only been applied to agree quite well, but that significant crosspolar compo- antennas, which are of limited spatial extent (a few nents were present, which are justifying accurate mod- wavelengths in size), but also to the computation of elling of polarisation diversity effects. This is illustrated propagation effects, which usually deal with objects that in Figure 4.7-2. are of significant spatial extent with respect to the wavelength (in fact a few 1000 wavelengths). A lot of work has been devoted in this COST Action to Physical optics models 'correcting' 2D methods to allow computations of 3D Paper [DMSW03] is comparing the standard Kirchhoff structures with nearly the same amount of computa- formulation with a novel appro