Novel Classification Model of the Mobile Radio Channel for Multi-Input-Multi-Output (MIMO) Antenna Systems



The antennas and propagation group has previously undertaken novel measurements description and modelling work regarding the Multi-Input-Multi-Output (MIMO) channel. Recently classification work has been undertaken based on simple radio metrics. Normally, the number of independent channels between transmitter and receiver is estimated by using eigenvalue analysis on the channel matrix. This analysis is rather complex and antenna system specific. The approach used here provides a more qualitative classification of dual directional radio channels in terms of good/poor support for parallel channels/diversity [Gerben Kuijpers, 2000 (a)]. K. Technical approach K.1 Channel classification model Since the support for parallel channels and the diversity gain are highly dependent on the multipath richness of the radio channel, different scattering scenarios are considered. Depending on local (around transmitter and another around receiver) scattering discs with same radius D and the distance between transmitter and receiver r, the scattering scenarios can be varied. K.2 Dispersion metrics When multiple antenna elements are used at both transmitter and receiver, a separate angular spread for each antenna array can be defined. Another measure for the angular dispersion is the standard error around the mean direction 7 [Gerben Kuijpers, 2000 (a)], which uses the normalised radius to the centre of gravity and provides a good measure for wide angular distributions. In this work the angular dispersion is characterised by the product of 7 at transmitter and receiver [Gerben Kuijpers, 2000 (a)]: 7=7tx 7rx. It is known that large angular dispersion at both transmitter and receiver is a condition for parallel channel support, but does not ensure this [J. Bach Andersen 2001 (g)]. To distinguish between these cases we propose the normalised delay spread parameter [Gerben Kuijpers, 2000 (a)] FJn=FJ/J0, i.e. the delay spread normalised to the delay of the line-of-sight component. Thus indicating the degree of 'scattering overlap' between transmitter and receiver. (Gerben Kuijpers, Patrick C.F. Eggers)
Effektiv start/slut dato31/12/200331/12/2003