Investigation of SINR gain in microcellular environment by use of antenna systems in mobile handsets

This work investigates the possible SINR gain, which can be obtained by using a low complexity pre-detection antenna system on a handheld phone. The antenna system consists of two antenna elements where the phase and amplitude is altered prior to an RF combining. The investigation is performed in an RF bandwidth corresponding to the one used in GSM. Three types of antenna elements has been investigated; 3/8 wavelength whip, a normal mode helical and a directive patch. The evaluation of the antenna system is based on measurements of incoming multipath fields received by a pair of antenna elements, which is mounted on a dummy handset. The measurements were carried out in a typical GSM-1800 urban microcell environment. By combining the measured signal at each antenna port the SINR gain has been calculated and evaluated for the antenna system. Both free space and in the presence of a user are investigated. The results shows the potential for a significant improvement of the SINR, when used in a interference limited microcell environment by a slow moving user.