JPH11313359A - Method and system for identifying location in mobile communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the precision for positioning a position and to increase the opportunity where a prescribed result can be obtained by collecting information required to identify a position of a mobile terminal, deciding one or plural position objects of the mobile terminal according to the position identifying method based on the collected information and using information of a sector to which the mobile terminal belongs among the decided position objects. SOLUTION: For example, each of base stations 1-1, 1-2, 1-3 grasps a terminal 2 in the unit of 6-division sectors, e.g. in a circumferential direction from an origin that is a position of each base station and sends identification information of the terminal 2 and each sector to a position management station 4 via a unification station 3. Furthermore, each of the base stations 1-1, 1-2, 1-3 sends distance information to the position management station 4 on request of the unification station 3 or the position management station 4. The position management station 4 calculates the position of the terminal 2 according to the TOA method based on the received distance information, obtains one or plural positions for position objects, and references sector information stored in a sector dependent terminal database 43 to decide the position of the terminal 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position specifying method and a position specifying device for specifying the position of a mobile terminal existing in a mobile communication system.

[0002]

2. Description of the Related Art In recent years, with the development of mobile communication technology, mobile terminals such as cellular phones, PHSs, and pagers have been supplied at low cost. As a result, services using these mobile terminals are diversifying. For example, there are services that require the location of the mobile terminal to be specified more than which base station accommodates the mobile terminal.

[0003] As a conventional general method for specifying the position of a mobile terminal, a Time of Arrival (TOA) method or a Time differ- ential (TOA) method is used.
ence of Arrival (TDOA) system.

In the TOA system, an incoming wave from one specific target (mobile terminal) is received at a plurality of observation points (base stations). The propagation time of the arriving wave at a certain observation point (= reception time−transmission time) is proportional to the distance from the observation point to a specific target, and the specific target is the propagation time around the observation point. It is on the circumference whose radius is the determined distance. Therefore, a circle is drawn for a plurality of observation points, and the position of the specific target is determined from the intersection. This TOA method requires a time at which a specific target starts transmitting radio waves. Further, when the number of observation points is two, two or more points of intersection of circles are generated and the position of the specific target cannot be uniquely specified. Therefore, three or more observation points are required.
That is, three or more base stations are required to receive transmission waves from the same mobile terminal.

[0005] The TDOA method also uses arrival times of incoming waves at a plurality of observation points, as in the TOA method. The TDOA method uses a difference between arrival times of two observation points. The difference between the arrival times of two observation points is
It is proportional to the difference (distance difference) between the distance between one observation point and the specific target and the distance between the other observation point and the specific target. The position of the specific target that gives the distance difference obtained for such two observation points is on a hyperbola whose parameter is the distance difference focusing on the positions of the two observation points. Therefore, in the TDOA method, the position of a specific target is estimated from the intersection of hyperbolas obtained for a combination of a plurality of observation points having different combinations of two points.
In the TDOA method, since the difference between the arrival times at the observation points is used, the time at which the observation target starts transmitting radio waves becomes unnecessary. In the TDOA method, in order to uniquely specify the position of a specific target, four or more base stations are required to receive transmission waves from the same mobile terminal.

[0006]

However, in mobile communication, a plurality of base stations cannot always receive radio waves from the same mobile terminal due to shadowing or fading by buildings or the like. That is, the minimum number of base stations (TO
3 base stations for A system, 4 base stations for TDOA system
Base station) cannot always receive radio waves from the same mobile terminal.

[0007] For example, if the number of base stations that can be received is only two in the TOA system, the estimated position of the mobile terminal is estimated as the intersection of two circles each having the base station as the origin. However, as described above, generally, there are two intersections of two circles, so that the position of the terminal cannot be uniquely determined. Similarly, when the number of base stations that can be received is three in the TDOA system, the position of the mobile terminal is estimated to be two.

That is, in the prior art, regardless of which of the TOA method and the TDOA method is applied, when the number of base stations that can be received is smaller than the number of base stations required for position identification, the position of the mobile terminal is uniquely determined. There was a problem that it was not possible.

[0009] Even if the number of received base stations is equal to or greater than the number of base stations required for position identification, if the arrival time at any one of the base stations is erroneously obtained due to noise or the like, the mobile station cannot be moved. The location of the terminal is obtained incorrectly. However,
Conventionally, even if the estimated position is incorrect, there is no method for confirming that, and the accuracy of the estimated position may be low.

Therefore, there is a need for a position specifying method and apparatus in a mobile communication system capable of uniquely determining the position of a mobile terminal.

There is also a need for a method and apparatus for specifying a position in a mobile communication system that can improve the accuracy of the estimated position of a mobile terminal.

[0012]

According to a first aspect of the present invention, there is provided a position determining method in a mobile communication system, comprising: a plurality of base stations each having a cell divided into at least two or more sectors; and at least one mobile terminal. In the mobile communication system configured from the above, information necessary for specifying the position of the mobile terminal is collected, and one or more position candidates of the mobile terminal are determined based on the collected information according to a predetermined position specifying method. And
The method is characterized in that the position of the mobile terminal is specified from the determined position candidates by using information on the sector to which the mobile terminal belongs.

According to a second aspect of the present invention, in a mobile communication system including a plurality of base stations and at least one mobile terminal, a position specifying method for a mobile terminal is required. Collecting information, determining one or more position candidates of the mobile terminal in accordance with a predetermined position specifying method with respect to the collected information, and identifying the mobile terminal in the past from the determined position candidates. The position of the mobile terminal is specified using the information on the position.

According to a third aspect of the present invention, there is provided a method for determining a position in a mobile communication system, comprising a plurality of base stations whose cells are divided into at least two or more sectors, and at least one mobile terminal. In body communication systems,
Collects information necessary for specifying the position of the mobile terminal, and for the collected information, determines one or more position candidates of the mobile terminal according to a predetermined position specifying method, and from among the determined position candidates, The position of the mobile terminal is specified using information on the sector to which the mobile terminal belongs and information on the position of the mobile terminal specified in the past.

According to a fourth aspect of the present invention, there is provided a position specifying apparatus for a mobile communication system, comprising: a plurality of base stations whose cells are divided into at least two or more sectors; and at least one mobile terminal. In body communication systems,
(1) Sector belonging terminal storage means for storing information on the sector to which the mobile terminal belongs, (2) information collecting means for collecting information necessary for specifying the position of the mobile terminal, and (3) collection thereof Temporary location determining means for determining one or more location candidates of the mobile terminal in accordance with a predetermined location identification method with respect to the determined information; and (4) a sector to which the mobile terminal belongs from among the determined location candidates. And a position determining means for specifying the position of the mobile terminal using the information of the mobile terminal.

According to a fifth aspect of the present invention, there is provided a mobile communication system including a plurality of base stations and at least one mobile terminal. A past specified position storage unit that stores information on the specified position; (2) an information collection unit that collects information necessary for specifying the position of the mobile terminal; Provisional position determining means for determining one or more position candidates of the mobile terminal in accordance with a predetermined position specifying method; and (4) using information of a position previously specified for the mobile terminal from the determined position candidates. And a position determining means for specifying the position of the mobile terminal.

According to a sixth aspect of the present invention, there is provided a position identifying apparatus for a mobile communication system, comprising: a plurality of base stations whose cells are divided into at least two or more sectors; and at least one mobile terminal. In body communication systems,
(1) Sector belonging terminal storage means for storing information of a sector to which the mobile terminal belongs, and (2) past specific position storage means for storing information of a position specified in the past for the mobile terminal. (3) information collecting means for collecting information necessary for specifying the position of the mobile terminal, and (4) one of the mobile terminals according to a predetermined position specifying method for the collected information.
Or a position provisional determination means for determining a plurality of position candidates,
(5) There is provided a position determining means for specifying the position of the mobile terminal using information on the sector to which the mobile terminal belongs and information on the position of the mobile terminal specified in the past from the determined position candidates. It is characterized by the following.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (A) First Embodiment Hereinafter, a first embodiment of a position specifying method and apparatus in a mobile communication system according to the present invention will be described in detail with reference to the drawings. The first embodiment basically employs the TOA method as a method for specifying the position of a mobile terminal.

FIG. 1 is a block diagram showing the configuration of the mobile communication system according to the first embodiment. In FIG. 1, the mobile communication system according to the first embodiment includes a mobile terminal 2 (FIG. 1) existing in its own cell C-1, C-2,.
Are shown only one).
-1, 1-2,..., 1-n (in FIG. 1, three base stations 1-
1-1 to 1-3) and the plurality of base stations 1-1, 1-2,
.., 1-n, and a location management station (PMC; PositionManageme) provided in association with the management station 3
nt Center) 4.

In the case of the first embodiment, each base station 1-
1, 1-2,..., 1-n are their own cells C
-1, C-2,..., Cn can be grasped in the sector unit obtained by dividing M (in FIG. 1, 6) in the circumferential direction with the self position as the origin. . That is, each of the base stations 1-1, 1-2,...
The mobile station 2 can know which sector the mobile station 2 is communicating with, and transmits information including the identification information of the mobile terminal and the identification information of the sector to the location management station 4 via the control station 3. is there.

Each of the base stations 1-1, 1-2,...
n is for transmitting the distance information to the position management station 4 via the control station 3 when distance information on the predetermined mobile terminal 2 is obtained from the control station 3 or the position management station 4. The distance information may be the propagation time of an incoming wave (= reception time−transmission time). In this case, the position management station 4 replaces the distance with the distance. Also, each of the base stations 1-1, 1-2,..., 1-n may transmit the propagation time of the arriving wave to the position management station 4 by replacing the propagation time with the distance.

.., 1-n
Although the transmission timing of the distance information and the mobile terminal information belonging to the sector may be the same, it is assumed that they are different in the following description.

Here, a base station that manages the mobile terminal 2 in a sector obtained by dividing a cell is well known, and it is also known that a base station in an existing system adopting the TOA system transmits distance information. Therefore, in FIG. 1, illustration of the detailed configuration of the base stations 1-1, 1-2,..., 1-n is omitted.

The supervising station 3 supervises the base stations 1-1 to 1-n and the position management station 4 and appropriately controls them. In relation to the characteristics of the first embodiment, each supervising station 3 controls each base station. 1-1, 1
,..., 1-n, it has only a relay function when transmitting the distance information from the sector and the mobile terminal information belonging to the sector to the location management station 4. Therefore, in FIG. ing.

The location management station 4 is composed of the base stations 1-1,.
-N to determine (estimate) the position of the mobile terminal 2 and, in some cases, also use the sector information of the base station in which the mobile terminal 2 is accommodated for the position determination. Things. When the location management station 4 functionally divides and shows the internal configuration, the base station information receiving section 4
1. Position calculation unit 42, sector belonging terminal database 43
And a position determining unit 44.

The base station information receiving section 41 adds new information to the sector terminal database 43 if the information given from the base stations 1-1,... The registered or registered information is corrected, and if it is distance information, it is given to the position calculation unit 42.

The position calculation unit 42 uses the TOA method
The position of the mobile terminal 2 is calculated. Here, even when the number of base stations to which the distance information to be used for the position calculation is two is calculated, two points (two places) are obtained as position candidates. When the number of base stations to which the distance information used for the position calculation is given is three or more, basically one position candidate is determined, but the intersection of each circle converges to one point. If not, a plurality of points are obtained as position candidates.

The sector belonging terminal database 43 stores information on the sector of the base station accommodating the mobile terminal 2.

When the position candidate of the mobile terminal 2 obtained by the position calculation unit 42 is one, the position determination unit 44 stores the information on the sector where the mobile terminal 2 is located, which is stored in the sector belonging terminal database 43. Based on the above, the validity is confirmed. In addition, the position determination unit 44 includes the position calculation unit 4
When the position candidates of the mobile terminal 2 obtained by the mobile terminal 2 are a plurality of points,
One point is determined based on the sector information where the mobile terminal 2 is located stored in the sector belonging terminal database 43. Further, when the number of base stations that have provided the distance information to be used for position calculation is one, the position determination unit 44 determines the sector information in which the mobile terminal 2 is located stored in the sector belonging terminal database 43. Is also used to roughly determine the position.

Hereinafter, the operation of the location management station 4 will be described with reference to the schematic flowchart of FIG.

When a certain mobile terminal 2 becomes a target of position estimation, the position management station 4 sends, via the control station 3, one or more base stations 1-1,... Collect distance information on terminal 2 (step 10)
0). And when the given distance information is plural,
The position calculation processing of the mobile terminal 2 according to the TOA method is performed (step 101). That is, the distance indicated by the distance information is defined as a radius, and a circle having the origin at the position of the base station that has transmitted the distance information is determined for all the base stations that have transmitted the distance information. When the number of transmitted base stations is three or more, one point intersecting with a circle of three or more base stations (a slight error is allowed) is set as a position candidate, and the number of base stations that have transmitted distance information is two. In Case of,
Two points intersecting the circles of the two base stations are set as position candidates. Here, when the number of base stations to which the distance information is given is three or more, if the intersection of each circle does not converge to one point, a plurality of points are obtained as position candidates. For example, such a case occurs when a radio wave on a straight path is blocked by an object or the like at a certain base station, and only a radio wave on a path due to reflection of a building or the like arrives.

It should be noted that even when the number of base stations that have transmitted the distance information is four or more, a position candidate may be obtained by using only the distance information of three of the base stations.

The location management station 4 determines whether or not the obtained location candidate of the mobile terminal 2 is one point (step 102).

If the position candidate of the mobile terminal 2 obtained is one, the validity is determined based on the sector information where the mobile terminal 2 is located stored in the sector belonging terminal database 43. After confirmation, the position candidate is determined as the position of the mobile terminal 2 (step 103).

If the determined position candidate of the mobile terminal 2 is inconsistent with the sector information, the following processing may be performed, for example. A flag that reveals contradiction is given, and the position candidate is determined as the position of the mobile terminal 2. Alternatively, among the other intersections obtained by the TOA method, one that belongs to the corresponding sector is determined as the position of the mobile terminal 2. Further, or this time, information that the position of the mobile terminal 2 could not be specified is output.

In the case where the obtained position candidates of the mobile terminal 2 are a plurality of points, or in the case where only one base station has given the distance information,
Reference is made to the sector information in which the mobile terminal 2 is located, which is stored in the sector belonging terminal database 43 (step 1).
04), determine the position of the mobile terminal 2 (step 10)
5). Specifically, for example, based on the case where the obtained position candidate of the mobile terminal 2 is a plurality of points, the position candidate belonging to the sector where the mobile terminal 2 is located is determined as the position of the mobile terminal 2. In the case where only one base station has given the distance information and the base station is the base station accommodating the target mobile terminal 2, for example, the given distance information in the sector to which the mobile terminal 2 belongs Is determined as the position of the mobile terminal 2 (in this case, all points on the circumference can be considered as position candidates). If the number of base stations to which the distance information is given is one and the base station does not accommodate the target mobile terminal 2, the position cannot be determined.

Next, in the prior art, when the number of base stations that transmitted distance information for which the position could not be specified is two, the manner of position determination will be specifically described with reference to FIGS. Will be described.

In the vicinity of the mobile terminal 2, base stations 1-1 to 1-1
-3. Normally, the distance R1 from the base station 1-1 to the mobile terminal 2 and the distance R from the base station 1-2 to the mobile terminal 2
2. The distance R3 from the base station 1-3 to the mobile terminal 2 is specified by each base station, and each base station 1-1, 1-2, 1-
A circle centered at 3 is drawn, and the position of the mobile terminal 2 is specified from the intersection of the three circles.

However, for example, if the radio wave is blocked between the base station 1-3 and the mobile terminal 2 by an obstacle such as a building, the distance R1 from the base station 1-1 to the mobile terminal 2
And only the distance R2 from the base station 1-2 to the mobile terminal 2 can be specified. It is assumed that the distance to the mobile terminal 2 cannot be specified in the other base stations 1-4 to 1-n.
In this case, the intersection points A1 and A2 of the two circles are obtained,
It is not possible to specify which is the position of the mobile terminal 2.

Here, it is assumed that the mobile terminal 2 is communicating in the sector S-1 of the base station 1-1. As described above, the location management station 4 knows in advance which area the sector of each base station covers, and knows the sector to which the mobile terminal 2 belongs. Therefore, the intersection A1 of the two intersections A1 and A2 which is in the area of the sector S-1
Is the position of the mobile terminal 2.

This will be described more specifically. The location management station 4
It is assumed that the positions (longitude and latitude) where the base stations 1-1 to 1-n are installed and the angle of the sector with respect to the longitude and latitude are known in advance. For example, as shown in FIG. 3A, it is assumed that the area of the coverage of a sector is known by an angle when the base station is the origin with the latitude being the X axis and the longitude being the Y axis.

The position management station 4 receives information on the distance R1 and the distance R2, and obtains a radius R1 centered on the position of the base station 1-1.
And a circle having a radius R2 centered on the position of the base station 1-2, and the intersection thereof is obtained. Generally, the intersection of two circles is 2
Since there are two, two solutions (intersections) A1 and A2 are obtained. When these intersections A1 and A2 are obtained as values in the rectangular coordinate system, the coordinates of the intersections A1 and A2 are converted to polar coordinates with the origin of the position of the base station 1-1 accommodating the mobile terminal 2. Convert. Thereby, as shown in FIG. 3B, angles P1 and P2 of intersections A1 and A2 with respect to the longitude X axis are obtained. Angles P1, P of these intersections A1, A2
2 and the angle range of the sector S-1 to which the mobile terminal 2 belongs, to find a solution. For example, as shown in FIG. 3C, if the angle P1 is within the range of the angle of the sector S-1, the intersection A1 is specified as the position of the mobile terminal 2.

As described above, according to the first embodiment,
Since the information of the sector to which the mobile terminal 2 belongs is used to specify the position of the mobile terminal 2, it is possible to improve the specification accuracy and to increase the chance of obtaining the specified result.

For example, by comparing the position calculated by the TOA method with the sector information, an erroneous position specifying result can be excluded. Further, in the TOA method, even when the position cannot be specified and the distance can be specified only by a small number of base stations, the position of the mobile terminal is specified by using sector information from a plurality of solution candidates. be able to.

In the above description, only the sector information of the base station accommodating the mobile terminal is used. However, the sector information of the base station not accommodating the mobile terminal may be used. good. For example, when the base station reports the distance information, it should also transmit the sector information, and the two intersections belong to the same sector of the base station accommodating the mobile terminal. Alternatively, the position of the mobile terminal may be specified with reference to the sector information of the base station that does not accommodate the mobile terminal.

(B) Second Embodiment Next, a second embodiment of the position specifying method and device in the mobile communication system according to the present invention will be described in detail with reference to the drawings. Note that the second embodiment is basically
The TDOA method is adopted as a method for specifying the position of a mobile terminal. Also, the second embodiment is characterized in that, similarly to the first embodiment, sector information at the base station to which the mobile terminal belongs is also used to specify the position of the mobile terminal. is there.

The configuration of the mobile communication system according to the second embodiment can also be represented by the above-described FIG. 1 in a block diagram.

However, each of the base stations 1-1,...
The difference from the first embodiment is that the information transmitted to the location management station 4 is not the distance information but the arrival time of a radio wave (wireless frame) from the same mobile terminal 2. The information of the sector to which the mobile terminal 2 belongs is stored in each base station 1-.
, 1-n are transmitted to the location management station 4 as in the first embodiment. Also, the location specifying process of the mobile terminal 2 in the location management station 4 is slightly different from that of the first embodiment.

Hereinafter, the operation of the location management station 4 according to the second embodiment will be described with reference to the schematic flowchart of FIG. In FIG. 4, the same and corresponding steps as those in FIG. 2 according to the first embodiment are denoted by the same reference numerals.

When a mobile terminal 2 is to be subjected to position estimation, the position management station 4 sends the mobile terminal 2 via the supervising station 3 the one or more base stations 1-1,. The arrival time information of the radio wave of the terminal 2 is collected (step 20).
0). Thereafter, based on the collected arrival time information, a difference in distance between the two base stations and the mobile terminal 2 is calculated for one or a combination of two or more sets of two base stations (step 201). Then, using the given distance difference value, a position calculation process of the mobile terminal 2 is performed according to the TDOA method (step 202). That is, an intersection point is obtained when a hyperbola focusing on the positions of the two base stations forming the set is drawn for all combinations of base stations for which the distance difference values have been obtained, and the base station that has transmitted the arrival time information is In the case of four or more, one point intersecting with a plurality of hyperbolas (a slight error is allowed) is regarded as a position candidate, and in the case where the number of base stations which transmitted the arrival time information is three, the position candidate is regarded as one. Since points cannot be narrowed down, a plurality of obtained intersections are set as position candidates. Here, even when the number of base stations to which the arrival time information is given is four or more, if the intersection of each hyperbola does not converge to one point, a plurality of points are obtained as position candidates. When the number of base stations to which the arrival time information is given is one, it is assumed that the position cannot be specified at the current position specifying timing.

It should be noted that the base station which has transmitted the arrival time information is 5
In the case of more than five stations, a position candidate may be obtained by using only the distance information of four stations, or a position candidate may be obtained by using all the distance information of five or more stations. It may be something.

The subsequent processing is the same as the processing in the first embodiment. That is, the location management station 4 determines whether or not the obtained location candidate of the mobile terminal 2 is one point (step 102). Then, when the obtained position candidate of the mobile terminal 2 is one point, the validity is confirmed based on the sector information in which the mobile terminal 2 is located stored in the sector belonging terminal database 43, The position candidate is determined as the position of the mobile terminal 2 (step 103). If the obtained position candidate of the mobile terminal 2 is a plurality of points, the information of the sector where the mobile terminal 2 is located stored in the sector belonging terminal database 43 is referred to (step 104), and the position of the mobile terminal 2 is determined. Is determined (step 105).

The second embodiment is different from the first embodiment in that TD
Although there are devices that apply the OA method or the TOA method, the second embodiment also provides the first method.
The same effect as the embodiment can be obtained. That is, since the information of the sector to which the mobile terminal 2 belongs is used for specifying the position of the mobile terminal 2, it is possible to improve the specification accuracy and to increase the chances of obtaining the specified result.

(C) Third Embodiment Next, a third embodiment of a position specifying method and apparatus in a mobile communication system according to the present invention will be described in detail with reference to the drawings. Note that the third embodiment is basically
The TOA method is used as a method for specifying the position of a mobile terminal. Further, the third embodiment is characterized in that the position information of the mobile terminal specified in the past is used for the position specifying process of the mobile terminal at the current timing.

The mobile communication system according to the first embodiment also has a mobile terminal 2 existing in its own cell C-1, C-2,... , 1-2, ..., 1-
n, and the plurality of base stations 1-1, 1-2, ..., 1-n
And a location management station 4 provided in association with the management station 3.

In the case of the third embodiment, each base station 1-
Each of 1, 1-2,..., 1-n may be capable of grasping the accommodated mobile station 2 in sector units.
The cells may not be divided into sectors.

Also in the third embodiment, the control station 3
Is for controlling the base stations 1-1 to 1-n and the location management station 4 and appropriately controlling them.

The location management station 4 is composed of the base stations 1-1,.
-N to determine (estimate) the position of the mobile terminal 2 and, in some cases, use the previously specified position information of the mobile terminal 2 for the current position determination. is there.

FIG. 5 is a block diagram showing the internal functional configuration of the location management station 4 in the third embodiment. The same reference numerals as in FIG. 1 denote the same or corresponding parts. I have. The location management station 4 in the third embodiment includes:
It comprises a base station information receiving section 41, a position calculating section 42, a past specific position database 45, and a position determining section 44.

The base station information receiving section 41 gives the distance information given from the base stations 1-1,..., 1-n via the control station 3 to the position calculating section 42.

The position calculation unit 42 uses the TOA method
The position of the mobile terminal 2 is calculated, and the position calculation unit 42 is the same as that of the first embodiment.

The past specified position database 45 stores the position information of the mobile terminal 2 specified in the past processing. The stored past specific position information may be only the specific position in the immediately preceding position specifying process, or may store a plurality of past specific positions. Also,
The time information at which the specific position is obtained is clarified by including the time information at which the specific position is obtained, or by determining the storage position at each immediately preceding timing.

When the position candidate of the mobile terminal 2 obtained by the position calculation unit 42 is one point, the position determination unit 44 of the third embodiment determines whether or not the mobile terminal 2 stored in the past specified position database 45 The validity is confirmed based on the specific position in the past. Also, the position determining unit 44
Is determined as one point based on the past specific position of the mobile terminal 2 stored in the past specific position database 45 when the position candidate of the mobile terminal 2 obtained by the position calculation unit 42 is a plurality of points. Things. Further, the position determining unit 4
4, when the number of base stations that have given distance information to be used for position calculation is one, the past specific position of the mobile terminal 2 stored in the past specific position database 45 is used to determine the position. It is determined roughly.

Hereinafter, the location management station 4 of the third embodiment will be described.
Will be described with reference to the schematic flowchart of FIG. In FIG. 6, the same as FIG.
Corresponding steps are denoted by the same reference numerals.

When a certain mobile terminal 2 is to be subjected to position estimation, the position management station 4 sends, via the control station 3, the mobile terminal 2 provided by one or a plurality of base stations 1-1,. Collect distance information on terminal 2 (step 10)
0). And when the given distance information is plural,
The position calculation processing of the mobile terminal 2 according to the TOA method is performed (step 101). Then, the position management station 4 determines whether or not the obtained position candidate of the mobile terminal 2 is one point (step 102). The processing of these steps 100 to 102 is the same as in the first embodiment.

When the obtained position candidate of the mobile terminal 2 is one point, the position management station 4 determines, based on the past specific position information on the mobile terminal 2 stored in the past specific position database 45, The validity is confirmed, the position candidate is determined as the position of the mobile terminal 2, and the process of updating the contents of the past specific position database 45 is executed (step 103). For example, if the distance between the current specific position and the past specific position is equal to or greater than a predetermined threshold, it is determined that the distance is not appropriate. The threshold value here may be changed according to the time difference between the current position specifying process and the past position specifying process. Note that the location management station 4 does not execute the updating process of the contents of the past specific location database 45 if it is not appropriate.

In the case where the obtained position candidates of the mobile terminal 2 are a plurality of points, or in the case where only one base station has given the distance information,
With reference to the past specific position information on the mobile terminal 2 stored in the past specific position database 45 (step 300), the position of the mobile terminal 2 is determined, and the content of the past specific position database 45 is updated. (Step 105).

Specifically, for example, based on the case where the obtained position candidate of the mobile terminal 2 is a plurality of points, it is close to a past specific position of the mobile terminal 2 (the distance is short, or a predetermined The position candidate whose angle is close) is determined as the position of the mobile terminal 2. Also, for example, the moving speed and the angular velocity are estimated from a plurality of past specific positions, and the distance from the immediately preceding specific position is the most appropriate position candidate in view of the moving speed and the angular velocity.
The position of the mobile terminal 2 is determined.

If the number of base stations to which the distance information has been given is one,
If the base station is a base station accommodating the target mobile terminal 2, for example, a position closest to a past specific position on a circumference determined by the distance is determined as the position of the mobile terminal 2.
In addition, for example, a moving speed or an angular velocity is estimated from a plurality of past specific positions, and a difference from the immediately preceding specific position on a circumference determined by a given distance determines a most appropriate position in view of the moving speed and the angular velocity. , The position of the mobile terminal 2.

When one base station has given distance information,
If the base station is not a base station accommodating the target mobile terminal 2, it is determined that the position cannot be determined, and the process of updating the contents of the past specific position database 45 is not executed.

Next, in the case where the number of base stations which have transmitted distance information for which the position could not be specified in the past is two, how the position is determined will be concretely described with reference to FIG. 1 and FIG. Will be described.

For example, the radio wave between the base station 1-3 and the mobile terminal 2 is blocked by an obstacle such as a building, and the distance R1 from the base station 1-1 to the mobile terminal 2 and the base station 1--1 2
It is assumed that only the distance R2 from the mobile terminal 2 to the mobile terminal 2 can be specified. In this case, the intersection points A1 and A2 of the two circles are obtained, but it is not possible to specify which is the position of the mobile terminal 2.

Here, the specific position immediately before the mobile terminal 2 is
If the intersection A1 is closer to the intersection A1 among the two intersections A1 and A2, the intersection A1 is specified as the position of the mobile terminal 2.

This will be described more specifically. The location management station 4
It is assumed that the positions (longitude and latitude) where the base stations 1-1 to 1-n are installed and the immediately preceding specific position are known in advance. For example, as shown in FIG. 7 (A), it is assumed that the user knows the specific position Cpos immediately before when the origin is the base station accommodating the mobile terminal 2 with the latitude as the X axis and the longitude as the Y axis. I do.

The position management station 4 receives information on the distance R1 and the distance R2, and obtains a radius R1 centered on the position of the base station 1-1.
And a circle having a radius R2 centered on the position of the base station 1-2, and the intersection thereof is obtained. Thereby, as shown in FIG. 7B, intersections A1 and A2 are obtained. This intersection A
1, the angle difference dP1 between A2 and the immediately preceding specific position Cpos,
The position candidate A1 having a small dP2 is specified as the position of the mobile terminal 2 as shown in FIG.

In the description with reference to FIG. 7, the angle difference is used for determining the distance from a specific position in the past. However, as described above, the absolute distance may be used for the determination. good. Further, as described above, information on the moving speed and the angular speed may be used.

As described above, according to the third embodiment,
Since the past specific position information on the mobile terminal 2 is used for specifying the current position of the mobile terminal 2, it is possible to improve the specification accuracy and increase the chances of obtaining the specification result.

For example, by comparing the position calculated by the TOA method with the past specific position information, an erroneous position specification result can be excluded. Further, in the TOA method, even when the distance cannot be specified by a small number of base stations whose position cannot be specified, the position of the mobile terminal can be determined by using past specific position information from a plurality of solution candidates. Can be specified.

Note that an average value of a plurality of positions during a certain period may be used as the past specific position information.

(D) Fourth Embodiment Next, a fourth embodiment of the position specifying method and device in the mobile communication system according to the present invention will be described in detail with reference to the drawings. In addition, this 4th Embodiment is basically,
The TDOA method is adopted as a method for specifying the position of a mobile terminal. Also, the fourth embodiment is characterized in that, similarly to the third embodiment, the location information of the mobile terminal identified in the past is used for the location identification processing of the mobile terminal at the current timing. It is.

The configuration of the mobile communication system according to the fourth embodiment is basically the same as the system according to the third embodiment.

However, each of the base stations 1-1,...
The third embodiment is different from the third embodiment in that the information transmitted to the location management station 4 is not the distance information but the arrival time of a radio wave (wireless frame) from the same mobile terminal 2. Although the detailed configuration of the location management station 4 can be represented in FIG. 6 described above, the location management processing of the mobile terminal 2 at the location management station 4 is slightly different from that of the third embodiment.

Hereinafter, the operation of the location management station 4 according to the fourth embodiment will be described with reference to the schematic flowchart of FIG. In FIG. 8, the same and corresponding steps as those in FIGS. 4 and 7 are denoted by the same reference numerals.

When a certain mobile terminal 2 is to be subjected to position estimation, the position management station 4 sends, via the control station 3, one or more base stations 1-1,... The arrival time information of the radio wave of the terminal 2 is collected (step 20).
0). Thereafter, based on the collected arrival time information, a difference in distance between the two base stations and the mobile terminal 2 is calculated for one or a combination of two or more sets of two base stations (step 201). Then, using the given distance difference value, a position calculation process of the mobile terminal 2 is performed according to the TDOA method (step 202). Steps 200 to 20 above
Process 2 is the same as in the second embodiment.

The subsequent processing is the same as the processing in the third embodiment. That is, when the obtained position candidate of the mobile terminal 2 is one point, the position management station 4 determines the position candidate based on the past specific position information on the mobile terminal 2 stored in the past specific position database 45. The validity is confirmed, the position candidate is determined as the position of the mobile terminal 2, and the process of updating the contents of the past specific position database 45 is executed (steps 102 and 103). Further, when the obtained position candidates of the mobile terminal 2 are a plurality of points, or when only one base station has given the distance information, the past of the mobile terminal 2 stored in the past specified position database 45 is used. Referring to the specific location information (step 300), the mobile terminal 2
And the past specific position database 4
5 is updated (step 105).

The fourth embodiment is different from the second embodiment in that TD
Although there are devices that apply the OA method or the TOA method, the fourth embodiment also provides the second device.
The same effect as the embodiment can be obtained. That is, since the past specific position information on the mobile terminal 2 is used for the current position specification of the mobile terminal 2, it is possible to improve the specification accuracy and increase the chances of obtaining the specification result. it can.

(E) Other Embodiments In each of the above embodiments, one of the sector information and the past specific position information is used in the current position specifying process. However, the sector information and the past specific position information are used. May be used in the current position identification processing. For example,
When a plurality of position candidates obtained by the TOA method or the like belong to the same sector, the position may be determined using past specific position information.

Although the present invention is intended for a mobile communication system such as a mobile phone, a PHS, a pager, etc., it is needless to say that the present invention can be applied to other mobile communication systems. In addition, it is needless to say that the position determination may be performed at another location instead of the location management station.

[0089]

As described above, according to the present invention, in a mobile communication system including a plurality of base stations and at least one mobile terminal, information necessary for specifying the position of the mobile terminal is collected. Then, for the collected information, one or more position candidates of the mobile terminal are determined according to a predetermined position identification method, and from the determined position candidates, information on the sector to which the mobile terminal belongs and Since the position of the mobile terminal is specified by using the information of the position specified in the past for the mobile terminal, the accuracy of the specification can be improved, and the chance of obtaining the specified result can be increased. Become.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a mobile communication system according to a first embodiment.

FIG. 2 is a flowchart illustrating a schematic process in a location management station according to the first embodiment.

FIG. 3 is an explanatory diagram of a position specification example using sector information according to the first embodiment;

FIG. 4 is a flowchart illustrating a schematic process in a location management station according to the second embodiment.

FIG. 5 is a block diagram illustrating a functional configuration of a location management station according to a third embodiment.

FIG. 6 is a flowchart illustrating a schematic process in a location management station according to the third embodiment.

FIG. 7 is an explanatory diagram of a position specifying example using past specific position information according to the third embodiment.

FIG. 8 is a flowchart illustrating a schematic process in a location management station according to the fourth embodiment.

[Explanation of symbols]

1-1 to 1-3: base station, 2: mobile terminal, 3: supervising station,
4 location management station, 41 base station information receiving section, 42 location calculation section, 43 terminal terminal belonging to sector, 44 location determination section, 45 specific past location database, C-1 to C-1
C-3: cell, S-1 to S-6: sector.

Claims (6)

[Claims] 1. A mobile communication system comprising a plurality of base stations whose cells are divided into at least two or more sectors and at least one mobile terminal, the mobile communication system comprising: Information is collected, and for the collected information, one or more position candidates of the mobile terminal are determined according to a predetermined position identification method, and from the determined position candidates, the mobile terminal belongs. A position specifying method in a mobile communication system, wherein the position of the mobile terminal is specified using sector information. 2. A mobile communication system comprising a plurality of base stations and at least one mobile terminal, wherein information necessary for specifying the position of the mobile terminal is collected, and the collected information is Determining one or more position candidates of the mobile terminal according to a predetermined position specifying method, and using the information of the position specified in the past for the mobile terminal from the determined position candidates, A position specifying method in a mobile communication system, which specifies a position of a mobile terminal. 3. A mobile communication system comprising a plurality of base stations whose cells are divided into at least two or more sectors and at least one mobile terminal, the mobile communication system comprising: Information is collected, and for the collected information, one or more position candidates of the mobile terminal are determined according to a predetermined position identification method, and from the determined position candidates, the mobile terminal belongs. A position specifying method in a mobile communication system, wherein the position of the mobile terminal is specified using sector information and information on a position specified in the past for the mobile terminal. 4. A mobile communication system comprising a plurality of base stations whose cells are divided into at least two sectors and at least one mobile terminal, wherein the mobile terminal belongs to a sector. Sector-affiliated terminal storage means for storing the information of the mobile terminal, information collecting means for collecting information necessary for specifying the position of the mobile terminal, and the mobile terminal Temporary position determining means for determining one or a plurality of position candidates, and position determining means for specifying the position of the mobile terminal from among the determined position candidates using information on a sector to which the mobile terminal belongs. And a location specifying device in the mobile communication system. 5. In a mobile communication system comprising a plurality of base stations and at least one mobile terminal, past specified position storage means for storing information on a position specified in the past for the mobile terminal. Information collecting means for collecting information necessary for specifying the position of the mobile terminal; and a position provisional unit for determining one or more position candidates of the mobile terminal in accordance with a predetermined position specifying method for the collected information. Moving means, comprising: determining means; and position determining means for specifying the position of the mobile terminal from the determined position candidates by using information on the position of the mobile terminal specified in the past. Position specifying device in body communication system. 6. A mobile communication system comprising a plurality of base stations whose cells are divided into at least two or more sectors and at least one mobile terminal, wherein the mobile terminal belongs to a sector to which the mobile terminal belongs. Sector-affiliated terminal storage means for storing the information of the mobile terminal, past specified position storage means for storing the information of the position specified in the past for the mobile terminal, and information necessary for specifying the position of the mobile terminal. Information collecting means for performing, a position provisional determining means for determining one or a plurality of position candidates of the mobile terminal in accordance with a predetermined position specifying method with respect to the collected information, and, from the determined position candidates, Position determining means for specifying the position of the mobile terminal using information on a sector to which the mobile terminal belongs and information on a position specified in the past for the mobile terminal. Localization apparatus in a mobile communication system according to claim.