Modelling polarisation diversity at the mobile terminal

Polarisation diversity has been used at the base station to create smaller antennas and reduce the environmental impact compared to that of the conventional spatial diversity. In the past, theoretical models have been developed to model polarisation diversity at the base station. At the mobile terminal polarisation diversity antennas are also an attractive option since the size limitations do not necessarily allow other forms of diversity to be implemented. There are many different scenarios at the mobile terminal including use of a switched combining receiver, low isolation between the antennas, conflicting gain patterns and a wider angular spread in the propagation environment. This therefore gives scope for a new theoretical model considering these scenarios, which are discussed. Further to this simulations were carried out to verify the new theory.