TIME-DIFFERENCE ESTIMATION METHOD FOR LOCATION BASED SERVICES IN A CELLULAR NETWORK

摘要

A time-difference estimation method for location based services in a cellular network comprises: estimating, by a terminal, the received power of a serving base station BS and the received power of other adjacent non-serving BSs, dividing the serving sector of the serving BS into a plurality of areas according to the estimation values; calculating, by the terminal, a compared parameter T and sending the compared parameter T to a location server via the serving BS; judging, by the location server, whether the compared parameter T is greater than a threshold or not, and if yes, then estimating, by the terminal, the power levels of the adjacent sectors of the serving BS and reporting these parameters to the system; determining, by the system according to said parameters, which specific area of the serving BS the terminal is located nearby; calculating user location information by the system or the terminal. With the present invention, defects of T-DOA and E-OTD based approaches can be compensated to improve precision for positioning a user who is located nearby the serving BS.