Characterisation of short-range microwave radio transponding channels for road-use debiting schemes

The authors present the results of the efforts of the PAMELA consortium to characterise microwave radio propagation channels likely to be encountered in any short-range digital data transponding link. They describe the geometry of the multipath problem for both directions of the link. The effects of antenna patterns on the transmission are implemented in the modelling by incorporating measurement antenna gain pattern data. The characterisation of the parameters of the modelling functions are derived for typical road-traffic scenarios. The channel modelling has been implemented by means of computer simulation programs and used to aid in making predictions of bit error rates under certain design conditions. Although the present modelling work has been constructed specifically for use in transponding systems, it has been made flexible and general in order that it can be applied to the general radio frequency link