time and space (Angle of Departure (AOD)/ 4.7.3.1 Introduction Arrival(AOA)) of the multipath field. This may be very valuable for the design and planning of present and future Deterministic propagation modelling is aimed at repro- systems using array antennas and/or space-time coding ducing or studying the actual physical radio propagation techniques such as MIMO systems. However, due to input process for a given environment. Such approach is database inaccuracies and limitations in the modelling of particularly suitable for manmade environments, where diffuse scattering and of the multipath propagation pro- radio waves interact with relatively simple, geometric cess in general, multidimensional performances of today's obstacles such as buildings and streets. In this case, the models are still quite poor. Some authors have therefore geometric and electromagnetic characteristics of the en- worked on the improvement of deterministic modelling vironment and of the radio link can be described and capabilities [DDGW03], [DEGDA04], [DEESGK02a], stored in files (databases) and the corresponding propa- [FuMa03], [BHHTO4a], [JePK05], [GhTI04], [Bert02]. gating field can be computed through analytical formulas Finally, deterministic models and their realistic propaga- and/or computer programs. The degree of accuracy and of tion simulation capabilities have been applied to system 'determinism' varies depending on the chosen approach. assessments such as network planning issues, system per- While some approaches can be properly considered formance assessments, positioning techniques etc. 'deterministic' others may be defined 'hybrid' or [CoWS04], [WHZL02], [ZBLL04], [Fusc04]. Deter- 'semi-statistical', as long as they leave off some determin- ministic and semi-deterministic field prediction models istic aspects and/or describe them through average, statis- and techniques, their performance, their pros and cons are tical parameters, thus decreasing complexity and described in this section. Applicative aspects and com- comput