Mobile station positioning system

摘要

The invention relates to a method for determining the position of a mobile station, a positioning system and a mobile station. According to the invention, a mobile station (21) receives signals from at least two base stations (22, 23, 24) and determines time differences of the clocks of the received signals. The mobile station (21) sends information about the time differences to a positioning service center (26) of the mobile communication system which calculates the position of the mobile station (21) on the basis of the time difference information and base station coordinates and clock information. With the method it is possible to measure signals the strengths of which remain below the minimum decoding level. According to the invention, it is also possible to measure bursts containing short training sequencies to improve timing measurement accuracy and measuring speed. The time difference measurement results obtained are transmitted from the mobile station to a base station advantageously by encoding the results in a signalling channel (SACCH) burst. The method enables quick position measuring at short intervals without substantially increasing the load on the mobile station or on the air interface.