Advanced Radio Channel Modelling, Sounding & Emulation

Summary form only given. This paper provides a survey of the current state-of-the-art in radio channel modelling, sounding and emulation. Starting form simple and well known channel modelling concepts, increasingly complex models are being developed leading to thorough understanding of one of the most advance channel models currently under development within the European project WINNER. Capabilities and limitations of the most popular narrow- and wideband channel model are also presented. Channel sounding is an indispensable prerequisite for the development and verification of radio channel model. The development from simple narrowband to the most advance multidimensional MIMO1 channel sounding principles are presented using code-, time-, and frequency-division multiplexing techniques. Today, high resolution channel parameter estimation algorithms such as MUSIC2, ESPRIT3, or SAGE4 are used to estimate the parameters of the multidimensional channel models. It is for this reason that these algorithms are briefly addressed emphasising their capabilities and limitations. Radio channel simulation and emulation are required to reduce system testing within field trials. Software simulation is widely used in the beginning of system design. However, performance evaluation of prototypes and products require real-time hardware emulation of the radio channel's time-variant characteristics. The paper addresses the most recent developments in radio channel emulation that allow the emulation of directional channels required for the performance evaluation of today's MIMO systems. This includes the trade-offs between simulation / emulation accuracy and complexity. Finally, the paper sheds light on the most recent developments concerning the standardisation of radio channel models within e.g. 3GPP, IEEE 802.11, IEEE 802.16 and the ITU-R.