Patent ID: 6134448
Filing Date: 2000-10-17
Classification: G01S,H04W

Abstract:
A positional information detecting system comprising:a wireless mobile terminal;a plurality of base stations for executing communications with said wireless mobile terminal; anda position managing station for executing communications with said wireless mobile terminal via said base stations,wherein said wireless mobile terminal comprises:an ID detection section for detecting base station identification information transmitted from each of said base stations;an intensity of electric field measuring section for measuring an intensity of electric field of received radio wave from each of said base stations; anda transmission signal generation section for converting one pair or a plurality of pairs of information comprised of the base station identification information of one or a plurality of base stations and the intensity of electric field of received radio wave from said base station, into a transmission signal to said base station,wherein said position managing station comprises:a signal demodulation section for demodulating a signal received from said wireless mobile terminal via said base station;a database for storing therein geographical information of a place where each base station of a plurality of base stations is located and a base station coefficient of each base station; anda position calculation section for determining a position of said wireless mobile terminal, with reference to said database, based on one pair or a plurality of pairs of information comprised of the base station identification information of one or a plurality of base stations outputted from said signal demodulation section and the intensity of electric field of received radio wave from said base station,wherein said position calculation section calculates a distance of a radius from said base station to said wireless mobile terminal, based on the intensity of electric field of the received radio wave from said base station and a base station coefficient of said base station stored in said database, by means of an approximate equation for calculating the distance of the radius from said base station to said wireless mobile terminal according to the intensity of electric field of the received radio wave from said base station and the base station coefficient, and then, determines the position of said wireless mobile terminal, based on the calculated distance of the radius and the geographical information of the places of said base stations stored in said database.