Impact of Constellation Design on Doppler - Rate Based Mt Positioning for Satellite - Umts

User position information is an important factor for achieving efficient operation of global wireless networks. It reduces the signalling load generated as a normal consequence of service provision. The basic constellation parameters that should be optimised in the design of the satellite segment of third generation wireless telecommunication networks (i.e., S-UMTS) to provide fast and accurate user location using a positioning technique based on time delay, Doppler shift and Doppler-rate measurements are discussed and analysed. In particular, orbit altitude, angle between planes and satellite spacing that provide the highest possible accuracy are derived from the simulation results presented in this paper.