Spherical Power Spectrum Model at the Mobile Terminal

antprop Today mobile terminals are often used indoor with the base station outdoors. At the mobile terminal the major part of the signal energy comes through openings in the building such as windows. Typically only one of the sides in a room has windows, and therefore a directive environment can be expected at the mobile terminal. Mobile terminal antennas used next to the head in speaking position will be directional due to the fact that part of the radiation pattern facing the head will be attenuated. For a directive antenna in a directive environment the performance will be dependent on the orientation of the antenna in the radio environment. To be able to calculate the directional performance of mobile terminals with a single or multiple antennas a new physical spherical outdoors to indoor power spectrum model has been proposed [M.B. Knudsen, G.F. Pedersen, 2001 (f)]. The model consists of one major scattering area in one direction and more uniformly distributed minor scatterers in the other directions. A verification of the proposed model has been performed by 60 data sets of spherical power spectrum measurements made in a typical urban environment. Using the new model the directional performance of mobile terminal antennas including a human operator has been investigated through directional MEG, branch power ratio and correlation calculations using spherical radiation pattern measurements of a mobile terminal including 42 different live persons. The accuracy of the calculated values has been verified by directly measured values using 200 persons with the mobile terminal walking in the same office-like environments as where the spherical power spectrum measurements were performed. (M. B. Knudsen, G. F. Pedersen)