Polarisation of Electromagnetic Waves Analysis for Application in Mobile Communication Systems

Abstract

The polarisation property of electromagnetic waves for applications in mobile communication systems has not been examined into detail yet. Due to multi-path effects and changes in the underlying coordinate systems of the involved antennas, the polarisation state of an electromagnetic wave at the receiving antenna of a mobile station is very likely to change. The presented project involves a data measurement and detailed visual investigation of these polarisation properties in the field of GSM mobile communication at the frequency band 1800 MHz. The measuring system mounted on a special car moves along a predefined trajectory around a GSM telecommunication cell. The collected data, which are received from a dual polarisation antenna, together with the information of the location, orientation and velocity of the system, which is provided by other sensors, is subsequently processed by the standard signal analysis hardware and the digital signal processing software, so that the polarisation behaviour of the received wave can be identified and visualized. The visualisation system is based on a digitized map into which the data received from GPS is inserted specifying the actual position of the measuring system. A particular polarisation state is simultaneously assigned to the position data in the digital map. The data analysis and signal filtering is performed to estimate multi-path propagation effects and to reduce the influence of them on the quality of the link. The results of this project could be for instance used in future generations of wireless mobile communication systems, where the polarisation dependent effects may contribute to increase reliability and capacity of the transmission service. This research was performed within the AMPER project, which is supported by the EU Commission.