System for detecting positional information

• US 6,134,448 A
• Filed: 12/30/1998
• Issued: 10/17/2000
• Est. Priority Date: 03/05/1996
• Status: Expired due to Fees

• Current Assignee: Locus LP, Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Locus LP, Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Koshima, Hiroaki, Shoji, Yoshiteru, Ohta, Yoshitaka
• Primary Examiner(s): Vo, Nguyen
• Assistant Examiner(s): RAMOS FELICIANO, ELISEO
• Application Number:
  US09/125,966
• Time in Patent Office: 657 Days
• Field of Search: 455/457, 455/456, 455/226.2, 701/300, 342/463, 342/450
• US Class Current: 455/456.2
• CPC Class Codes: G01S 5/0054 of actual mobile position, i.e. position calculation on base station
• CPC Class Codes: G01S 5/02529 not involving signal parameters, i.e. only involving identifiers
• CPC Class Codes: H04W 16/32 Hierarchical cell structures
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A mobile terminal has a simple construction in a mobile communication system of a small-zone system. The mobile terminal 1 transmits base station identification information transmitted from base stations 2a through 2d and information of the intensity of electric field of received radio wave from the base station to a position managing station, while the position managing station specifies the current position of the mobile terminal, based on the above-mentioned information by means of a relational expression of the intensity of electric field and a distance between a point of transmission and reception and a database of the base station. With the simple construction of the mobile terminal 1, the current position of the mobile terminal 1 can be specified with higher accuracy. Further, the mobile terminal 1 transmits the base station identification information of the plurality of base stations and the intensity of electric field of the received radio wave from the base station to the position managing station, the current position of the mobile terminal 1 can be specified with higher accuracy.

Claims

1. A positional information detecting system comprising:

a wireless mobile terminal;

a plurality of base stations for executing communications with said wireless mobile terminal; and

a 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; and

a 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; and

a 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.

2. The positional information detecting system as claimed in claim 1,

wherein said position managing station further comprises a mobile terminal calling section for originating a call to said wireless mobile terminal.

3. The positional information detecting system as claimed in claim 2,

wherein said transmission signal generation section converts one pair of information into a DTMF signal as said transmission signal, and

said signal demodulation section demodulates the received DTMF signal into said one pair of information.

4. The positional information detecting system as claimed in claim 1,

wherein said transmission signal generation section converts one pair of information into a DTMF signal as said transmission signal, and

said signal demodulation section demodulates the received DTMF signal into said one pair of information.