Method and system for detecting the position of mobile station

• US 20030114169A1
• Filed: 03/07/2002
• Published: 06/19/2003
• Est. Priority Date: 12/14/2001
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Fujiwara, Kei, Yanagi, Kenji, Okamura, Takeo, Nakamura, Taiji, Kawashima, Takeshi
• Application Number:
  US10/093,642
• Publication Number:
  US 20030114169A1
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 3/48 the waves arriving at the antennas being continuous or intermittent and the phase difference of signals derived therefrom being measured
• CPC Class Codes: G01S 5/0054 of actual mobile position, i.e. position calculation on base station
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

In a mobile communication system including a plurality of base stations 10 and an MS position administrating station 30 connected to each of the base stations via a communication network, at least one of the base stations detects an arrival angle of a position detection signal from a mobile station and an average received power or propagation distance, and transmits the detected values as position detection parameters to the MS position administrating station, and the MS position administrating station detects the position of the mobile station on the basis of the position detection parameters and map information of an area including the base station.

Claims

1. A method of detecting the position of a mobile station by using abase station for mobile communication having an adaptive array antenna comprising a plurality of antenna elements, comprising:

a step of detecting position detection parameters including an arrival angle and an average received power of a position detection signal from the mobile station by a base station which receives the position detection signal; and

a step of calculating the position of the mobile station on the basis of said position detection parameters and map information of an area including said base station by the base station or any of stations constructing a mobile communication system.

2. The method of detecting the position of a mobile station according to claim 1, wherein the step of detecting the position detection parameters comprises:

a first step of detecting position detection parameters by a first adaptive algorithm for optimizing weight to be given to a received signal from each of the antenna elements with respect to said position detection signal;

a second step of measuring an average received power by a second adaptive algorithm for optimizing weight to be given to a received signal from each of the antenna elements with respect to a received signal from a specific arrival angle direction detected by said first step; and

a third step of verifying said position detection parameters by comparing the average received power measured in said first step with the average received power measured in said second step.

3. The method of detecting the position of a mobile station according to claim 2, wherein the step of detecting the position detection parameters includes a fourth step of repeating, when said position detection parameters are determined as inappropriate in said third step, measurement of the average received power while changing an arrival angle to be optimized in accordance with said second adaptive algorithm, detecting an average received power and an arrival angle as peak values, and setting the detected values as new position detection parameters.

4. The method of detecting the position of a mobile station according to claim 3, wherein the step of detecting the position detection parameters includes a step of detecting an arrival angle of an interference wave in a state where weight to be given to a received signal from each of the antenna elements is optimized by said first adaptive algorithm, and

said new position detection parameters are detected by eliminating the arrival angle of said interface wave in said fourth step.

5. The method of detecting the position of a mobile station according to claim 1, wherein said position calculating step comprises:

a step of calculating a straight distance from said base station to said mobile station on the basis of an average received power indicated in the position detection parameters and a preliminarily given propagation distance characteristic;

a step of determining the presence or absence of an obstacle existing between said base station and said mobile station on the basis of map information of an area including said base station; and

a step of specifying the position of the mobile station on the map on the basis of the position of said base station, the arrival direction indicated in the position detection parameters, and said straight distance in the case where it is determined that there is no obstacle between said base station and the mobile station.

6. The method of detecting the position of a mobile station according to claim 5, further comprising a step of specifying, when it is determined that there is an obstacle between said base station and the mobile station, reflection points of said position detection signal and a propagation path on the basis of said map information, calculating a propagation distance by applying a reflection coefficient of each of the reflection points which are preliminarily modeled, and specifying the position of the mobile station on the map.

7. The method of detecting the position of a mobile station according to claim 5, further comprising a step of setting an error range by using the position of the mobile station specified in said position calculating step as a center.

8. A method of detecting the position of a mobile station by using abase station for mobile communication having an adaptive array antenna comprising a plurality of antenna elements, comprising:

a step of detecting position detection parameters including an arrival angle and a propagation distance of a position detection signal from a mobile station by abase station which receives the position detection signal; and

a step of calculating the position of said mobile station on the basis of said position detection parameters and map information of an area including said base station by the base station or any of stations constructing a mobile communication system.

9. The method of detecting the position of a mobile station according to claim 8, wherein the step of detecting said position detection parameters comprises:

a first step of detecting a propagation distance of the position detection signal from propagation required time of said position detection signal;

a second step of detecting an arrival angle and an average received power of the position detection signal by a first adaptive algorithm for optimizing weight to be given to a received signal from each of the antenna elements with respect to said position detection signal;

a third step of measuring an average received power by a second adaptive algorithm for optimizing weight to be given to a received signal from each of the antenna elements with respect to the received signal from the specific arrival angle direction detected in said second step; and

a fourth step of verifying said arrival angle by comparing the average received power measured in said second step with the average received power measured in said third step.

10. The method of detecting the position of a mobile station according to claim 9, wherein the step of detecting said position detection parameters includes a fifth step of repeating, when it is determined in said fourth step that said arrival angle is inappropriate, measurement of the average received power while changing an arrival angle to be optimized in accordance with said second adaptive algorithm, detecting an average received power and an arrival angle as peak values, and setting the detected arrival angle and radio wave propagation distance as new position detection parameters.

11. The method of detecting the position of a mobile station according to claim 10, wherein the step of detecting said position detection parameters includes a step of detecting an arrival angle of an interference wave in a state where weight to be given to a received signal from each of the antenna elements is optimized by said first adaptive algorithm, and

said new position detection parameters are detected by eliminating the arrival angle of said interface wave in said fifth step.

12. The method of detecting the position of a mobile station according to claim 8, wherein said position calculating step comprises:

a step of determining the presence or absence of an obstacle existing between said base station and said mobile station on the basis of map information of an area including said base station; and

a step of specifying, when it is determined that there is no obstacle between said base station and the mobile station, the position of the mobile station on the map on the basis of the position of said base station, said arrival direction of the radio wave and said propagation distance indicated in said position detection parameters.

13. The method of detecting the position of a mobile station according to claim 12, further comprising a step of specifying, when it is determined that there is an obstacle between said base station and the mobile station, reflection points of said position detection signal and a propagation path in accordance with said map information, and specifying the position of the mobile station on the map.

14. A base station for mobile communication comprising:

a plurality of antenna elements;

a plurality of weight adjusting units corresponding to said antenna elements; and

an adaptive processor for controlling a weight value to be set in each of the weight adjusting units,

wherein said adaptive processor has means for detecting an arrival angle of a position detection signal transmitted from a mobile station and an average received power or propagation distance of said position detection signal, and outputting the detected values as position detection parameters.

15. The base station according to claim 14, wherein said adaptive processor has means for verifying said position detection parameters by comparing the average received power detected by a first adaptive algorithm for optimizing a weight value with respect to a position detection signal transmitted from the mobile terminal with an average received power detected by a second adaptive algorithm for optimizing a weight value with respect to a received signal from a specific arrival angle direction detected by said first adaptive algorithm.

16. A mobile communication system comprising a plurality of base stations and a position administrating station connected to each of said base stations via a communication network,

wherein at least one of said base stations has means for detecting an arrival angle of a position detection signal transmitted from a mobile station and an average received power or propagation distance of said position detection signal, and transmitting the detected values as position detection parameters to said position administrating station, and

said position administrating station is provided with means for detecting the position of the mobile station on the basis of the position detection parameters received from the base station and the map information of the area including the base station.

17. The mobile communication system according to claim 16, wherein said position detecting means calculates a straight distance from said base station to said mobile station on the basis of an average received power indicated in said position detection parameters and a formula expressing propagation distance characteristic preliminarily given, determines the presence or absence of an obstacle between the base station and the mobile station on the basis of map information of an area including said base station, specifies reflection points and a propagation path of the position detection signal in accordance with said map information when it is determined that there is an obstacle, calculates the propagation distance by using preliminarily modeled reflection coefficients of each of reflection points, and specifies the position of the mobile station on the map.

18. The mobile communication system according to claim 16, wherein said position detecting means determines the presence or absence of an obstacle between the base station and a mobile station on the basis of said position detecting parameters and map information of the area including said base station, specifies a reflection points of said position detection signal and a propagation path on the basis of said map information when it is determined that there is an obstacle, and estimates the position of said propagation distance along the propagation path as the position of the mobile station.