WO2010122778A1 - Positional information calculation system, method, and device, and correction value calculation device and program - Google Patents

Abstract

A positional information calculation system which is provided with a plurality of base station devices and a positional information calculation device for calculating positional information relating to a mobile station device. The mobile station device is provided with: a reception means which receives signals synchronously transmitted from two of the base station devices; an observation time difference calculation means which calculates the observation time difference between the two signals received by the reception means; and an observation time difference transmission means which transmits the observation time difference to the positional information calculation device. The positional information calculation device is provided with a correction value storage means which associates a correction value to be used to correct the error of the observation time difference with identification information relating to a base station device indicating each of the base station devices and stores the correction value and in which the error is generated due to a propagation time from when a signal is transmitted by the synchronous transmission means of each base station device till when the signal arrives at the antenna of the base station device.

Description

POSITION INFORMATION CALCULATION SYSTEM, METHOD, AND DEVICE, CORRECTION VALUE CALCULATION DEVICE, AND PROGRAM

The present invention relates to a position information calculation system, a position information calculation method, a position information calculation apparatus, a correction value calculation apparatus, and a program that include a plurality of base station apparatuses and a position information calculation apparatus that calculates position information of a mobile station apparatus. .
This application claims priority based on Japanese Patent Application No. 2009-104421 for which it applied on April 22, 2009, and uses the content here.

Conventionally, in a mobile phone network, a system for calculating position information of a mobile station device by OTDOA (Observed Time Difference of Arrival) has been put into practical use (for example, see Non-Patent Document 1). OTDOA is an observation time difference between a pair of downlink signals transmitted from two base station devices at the same time in the mobile station device.

The calculation of position information by conventional OTDOA is performed as follows.
FIG. 6 is a diagram illustrating a geographical arrangement of the base station device and the mobile station device.
FIG. 6 shows the positional relationship between the base station device 10-1, the base station device 10-2, and the mobile station device 20, and shows the state where the mobile station device 20 is located in the base station device 10-1. Yes.
In FIG. 6, a straight line passing through a point where the base station apparatus 10-1 exists (hereinafter referred to as point A) and a point where the base station apparatus 10-2 exists (hereinafter referred to as point B) A straight line that passes through the midpoint between point A and point B and is parallel to the ground surface and perpendicular to the X axis is taken as the Y axis.

At this time, in the mobile station device 20, when the observation time difference between the signals transmitted in synchronization between the base station device 10-1 and the base station device 10-2 is measured, the point where the mobile station device 20 exists (hereinafter referred to as point P Is present somewhere on the hyperbola H with the point A and the point B as the focal point where the observation time difference is constant. The hyperbola H is expressed by equation (1).

However, a and b show the hyperbolic coefficient.
Next, a method for calculating the coefficients a and b will be described.
When the distance represented by the difference between the distance between the points AP and the distance between the points BP is d, the coefficient a can be calculated by calculating Expression (2).

Further, the coefficient b can be calculated by calculating the expression (3) using the distance D between the points AB and the coefficient a calculated by the expression (2).

Thereby, the hyperbola H can be determined by calculating the coefficients a and b of the hyperbola H.
Similarly, an observation time difference due to a combination other than the combination of the base station 10-1 and the base station 10-2 is measured, and a function of a hyperbola H ′ (not shown) in which the observation time difference is constant is derived, and the hyperbola H And the hyperbola H ′, the point P where the mobile station device exists can be obtained.

3GPP TS 25.305 Stage 2 functional specification of User Equipment (UE) positioning in UTRAN

However, since the base station device transmits a signal via the antenna connected by the feeder line, the observation time difference of the signal in the mobile station device includes the feeder length from the wireless output of the base station device to the antenna, the wireless unit The error due to the propagation time when the is installed remotely is included, and accurate position information cannot be calculated.
For example, referring to FIG. 6, because of an error due to propagation time, the distance represented by the difference between the distance between the points AP and the distance between the points BP is calculated as d ′ including an error with respect to d. For this reason, the position of the mobile station apparatus 20 is calculated as a point on the hyperbola I different from the hyperbola H.
The present invention has been made in view of the above points, and an object thereof is to provide a position information calculation system, a position information calculation method, a position information calculation apparatus, a correction value calculation apparatus, and a program for calculating accurate position information. There is to do.

The present invention has been made to solve the above-described problem, and is a position information calculation system including a plurality of base station apparatuses and a position information calculation apparatus that calculates position information of a mobile station apparatus,
(i) Each of the base station devices includes synchronization transmission means for transmitting a signal to the mobile station device via an antenna at the same time as other base station devices,
(ii) The mobile station apparatus receives a signal synchronously transmitted from two base station apparatuses, an observation time difference calculation means for calculating an observation time difference between the two signals received by the reception means, Observation time difference transmission means for transmitting the observation time difference calculated by the observation time difference calculation means to the position information calculation device,
(iii) The position information calculation device is used to correct an observation time difference error calculated by an observation time difference calculation unit of the mobile station device in association with base station device identification information indicating each of the plurality of base station devices. Correction value storage means for storing a correction value, wherein the error is caused by a propagation time until the signal transmitted by the synchronous transmission means of the base station apparatus reaches the antenna of the base station apparatus. The mobile station based on the value storage means, the observation time difference reception means for receiving the observation time difference from the mobile station device, the observation time difference received by the observation time difference reception means, and the correction value stored in the correction value storage means There is provided a position information calculation system including position information calculation means for calculating position information of an apparatus.

The present invention is also a location information calculation method using a location information calculation system comprising a plurality of base station devices and a location information calculation device for calculating location information of a mobile station device, wherein each of the base station devices Synchronous transmission means transmits a signal to the mobile station apparatus via an antenna at the same time as other base station apparatuses, and the reception means of the mobile station apparatus transmits signals transmitted synchronously from the two base station apparatuses. The observation time difference calculating means of the mobile station apparatus calculates the observation time difference of the two signals received by the receiving means, and the observation time difference transmission means of the mobile station apparatus is the observation calculated by the observation time difference calculation means The time difference is transmitted to the position information calculation device, the observation time difference reception means of the position information calculation device receives the observation time difference from the mobile station device, and the position information calculation means of the position information calculation device For correcting the error of the observation time difference generated by the observation time difference received by the observation time difference receiving means and the propagation time until the signal transmitted by the synchronous transmission means of the base station apparatus reaches the antenna of the base station apparatus. There is also provided a position information calculation method for calculating position information of the mobile station apparatus based on a correction value to be used.

In addition, the present invention is a position information calculation apparatus that calculates position information of the mobile station apparatus based on reception signals from a plurality of base station apparatuses in the mobile station apparatus, and shows each of the plurality of base station apparatuses Corresponding to base station apparatus identification information, correction value storage means for storing a correction value used for correcting an error of the observation time difference calculated by the observation time difference calculation means of the mobile station apparatus, wherein the error is the base station apparatus Correction value storage means that is generated by a propagation time until the signal transmitted by the synchronous transmission means reaches the antenna of the base station apparatus, and a signal for the set of two base station apparatuses from the mobile station apparatus Based on the observation time difference receiving means for receiving the observation time difference, the observation time difference received by the observation time difference receiving means, and the correction value stored in the correction value storage means. A position information calculation means for calculating the position information of the position information calculating device comprising providing.

According to another aspect of the present invention, there is provided a location information calculation device that calculates location information of the mobile station device based on signals received by the mobile station device from a plurality of base station devices, and a base station that represents each of the plurality of base station devices. Corresponding to apparatus identification information, correction value storage means for storing a correction value used for correcting an error of the observation time difference calculated by the observation time difference calculation means of the mobile station apparatus, the error being a synchronization of the base station apparatus Correction value storage means, which is generated by the propagation time until the signal transmitted by the transmission means reaches the antenna of the base station apparatus, the observation time difference of the signal from the mobile station apparatus to the two base station apparatuses Observation time difference receiving means for receiving the observation time difference, the position information of the mobile station apparatus is calculated based on the observation time difference received by the observation time difference receiving means and the correction value stored by the correction value storage means. Position information calculating means for also provides programs for operating as.

Further, according to the present invention, a signal transmitted by each of a plurality of base station devices is synchronously transmitted from the two base station devices received by the mobile station device according to a propagation time until the signal reaches the antenna of the base station device. A correction value calculation device for calculating a correction value used for correcting an error occurring in the observation time difference of the received signal, the observation time difference receiving means for receiving the observation time difference from the mobile station device, the mobile station device, and Round-trip propagation delay time receiving means for receiving round-trip propagation delay time between antennas of the mobile station apparatus and the base station apparatus from any round-trip propagation delay time transmitting means of the base station apparatus where the mobile station apparatus is located Correction value calculation for calculating the correction value based on the observation time difference received by the observation time difference receiving means and the round-trip propagation delay time received by the round-trip propagation delay time receiving means. Also provided correction value calculating apparatus comprising a means.

Further, according to the present invention, a signal transmitted by each of a plurality of base station devices is synchronously transmitted from the two base station devices received by the mobile station device according to a propagation time until the signal reaches the antenna of the base station device. A correction value calculation device for calculating a correction value used for correcting an error occurring in the observation time difference of the received signal, an observation time difference receiving means for receiving the observation time difference from the mobile station device, the mobile station device, and the mobile station device A round-trip propagation delay time receiving means for receiving a round-trip propagation delay time between the antenna of the mobile station apparatus and the base station apparatus from any of the base station apparatuses in which the mobile station is located, and an observation received by the observation time difference receiving means A program that operates as a correction value calculating unit that calculates the correction value based on the time difference and the round-trip propagation delay time received by the round-trip propagation delay time receiving unit Subjected to.

According to the present invention, the position information calculation device calculates the position information of the mobile station device based on the observation time difference in the mobile station device and the correction value stored in the correction value storage means. Thereby, it is possible to correct the observation time difference in the mobile station apparatus and calculate accurate position information.

It is a block diagram of the positional information calculation system by one Embodiment of this invention. It is a schematic block diagram which shows the structure of a positional information calculation system. It is a figure which shows the correction value table which a correction value memory | storage part memorize | stores. It is a 1st sequence diagram which shows operation | movement of a positional infomation calculation system. It is a 2nd sequence diagram which shows operation | movement of a positional infomation calculation system. It is a figure which shows the geographical arrangement | positioning with a base station apparatus and a mobile station apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram of a position information calculation system according to an embodiment of the present invention.
The location information calculation system includes a plurality of base station devices 10-1 to 10-3 and a location information calculation device 30 that calculates location information of the mobile station device 20.
Here, for the sake of explanation, the case where the position information calculation system includes three base station apparatuses will be described as an example. However, the position information calculation system actually includes three or more base station apparatuses.
Each of the base station devices 10-1 to 10-3 has a cell which is a communication range in the base station device, and mediates communication of the mobile station device 20 located in the cell of the own device.
The mobile station device 20 is located in any cell of the base station devices 10-1 to 10-3, and communicates with the position information calculation device 30. In FIG. 1, the mobile station device 20 is located in the cell A of the base station device 10-1.
The location information calculation device 30 receives information from the base station devices 10-1 to 10-3 and the mobile station device 20, and calculates the location information of the mobile station device 20 based on the information.

FIG. 2 is a schematic block diagram showing the configuration of the position information calculation system.
The base station apparatuses 10-1 to 10-3 include a communication unit 11 (synchronous transmission unit, round-trip propagation delay time transmission unit) and an RTT measurement unit 12 (round-trip propagation delay time measurement unit).
The communication unit 11 communicates with the mobile station device 20 via an antenna, and communicates with the position information calculation device 30 via an upper line (Backhaul line) such as an optical line. In addition, the communication unit 11 transmits a broadcast signal to the mobile station device 20 at the same time in synchronization with the other base station devices 10-1 to 10-3.
The RTT measurement unit 12 measures a round trip time (RTT: Round Trip Time) between the antennas of the base station apparatus and the mobile station apparatus.

The mobile station apparatus 20 includes a communication unit 21 (reception unit, observation time difference transmission unit) and an OTDOA calculation unit 22 (observation time difference calculation unit).
The communication unit 21 receives signals from the base station apparatuses 10-1 to 10-3, and also passes through the base station apparatus (any one of 10-1 to 10-3, 10-1 in FIG. 1) To communicate with the position information calculation device.
The OTDOA calculation unit 22 calculates an observation time difference (OTDOA) between signals transmitted synchronously from two base station apparatuses.

The position information calculation device 30 includes a communication unit 31 (observation time difference reception unit, round-trip propagation delay time reception unit), a correction value calculation unit 32 (correction value calculation unit), a correction value registration unit 33 (correction value registration unit), and a correction value. A storage unit 34 (correction value storage unit) and a position information calculation unit 35 (position information calculation unit) are provided.
The communication unit 31 communicates with the base station apparatuses 10-1 to 10-3 via the upper line, and communicates with the mobile station apparatus 20 via the upper line and the base station apparatuses 10-1 to 10-3. Do.
The correction value calculation unit 32 calculates a correction value used for calculation of position information based on information received from the base station apparatuses 10-1 to 10-3 and the mobile station apparatus 20.
The correction value registration unit 33 registers the correction value calculated by the correction value calculation unit 32 in the correction value storage unit 34.
The correction value storage unit 34 stores the coordinates, cell types, and correction values of the base station devices 10-1 to 10-3 in association with the cell IDs that identify each of the base station devices 10-1 to 10-3. Store the value table.
The position information calculation unit 35 calculates the position of the mobile station device 20 based on the information received from the mobile station device 20 and the information stored in the correction value table.

FIG. 3 is a diagram illustrating a correction value table stored in the correction value storage unit.
The correction value table is associated with cell IDs for identifying each of the base station devices 10-1 to 10-3, coordinates indicating the positions of the base station devices 10-1 to 10-3, and the base station devices 10-1 to 10-10. -3, the cell type indicating the cell type, the propagation time until the signal transmitted by the communication unit 11 of the base station apparatuses 10-1 to 10-3 reaches the antenna of the own (base station) apparatus, that is, the signal Stores a correction value used for correcting an error due to the time of propagation through the path from the communication unit 11 to the antenna.
Here, it is assumed that the cell of base station apparatus 10-1 is a minute cell, and the signal propagation time to the antenna of base station apparatus 10-1 is negligibly small. Therefore, the correction value associated with the cell A indicating the base station device 10-1 is zero. Here, the micro cell refers to a narrow range cell having a radius of about several tens of meters, such as a pico cell or a femto cell.
The cells of the base station apparatuses 10-2 and 10-3 are macro cells, and their correction values are not registered. Here, the macro cell indicates, for example, a wide range cell having a radius of about several kilometers. The size of the cell is mainly determined by the output power of the base station apparatus.

In the position information calculation system, the communication unit 11 of the base station apparatuses 10-1 to 10-3 transmits a signal to the mobile station apparatus 20 via the antenna at the same time as the other base station apparatuses 10-1 to 10-3. , The communication unit 21 of the mobile station device 20 receives the signals transmitted synchronously from the two base station devices, and the OTDOA calculation unit 22 calculates the observation time difference between the two signals received by the communication unit 21. . When the OTDOA calculation unit 22 calculates the observation time difference, the communication unit 21 transmits the observation time difference calculated by the OTDOA calculation unit 2 to the position information calculation device 30.
Next, the communication unit 31 of the position information calculation device 30 receives the observation time difference from the mobile station device 20, and the position information calculation unit 35 stores the observation time difference received by the communication unit 31 and the correction value storage unit 34. Based on the correction value used for correcting the error of the observation time difference due to the propagation time until the signal transmitted by the communication unit 11 of the base station apparatuses 10-1 to 10-3 reaches the antenna, the mobile station apparatus 20 Calculate location information.
Thereby, accurate position information can be calculated.

Next, the operation of the position information calculation system will be described.
First, in order to calculate the position information of the mobile station device 20, it is necessary to calculate the correction value of each of the base station devices 10-1 to 10-3. Hereinafter, a method for calculating correction values of the base station apparatuses 10-1 to 10-3 will be described.

FIG. 4 is a first sequence diagram illustrating the operation of the position information calculation system.
Here, a case where the correction value of base station apparatus 10-2 is calculated will be described as an example.
When the mobile station device 20 is located in the base station device 10-1 (first base station device) having the cell A which is a minute cell, the communication unit 31 of the location information calculation device 30 -1 is transmitted to the mobile station apparatus 20 via the −1 command to calculate the observation time difference between the base station apparatus 10-1 and the base station apparatus 10-2 (second base station apparatus) (step S1).
When the position information calculation device 30 transmits an observation time difference calculation command, the communication unit 21 of the mobile station device 20 receives the calculation command (step S2). Thereby, the communication unit 21 of the mobile station device 20 waits for reception of broadcast signals from the base station devices 10-1 and 10-2.

The communication units 11 of the base station apparatuses 10-1 and 10-2 are synchronized and transmit broadcast signals at the same time, periodically or in accordance with an instruction from the position information calculation apparatus 30 (step S3).
When the base station devices 10-1 and 10-2 transmit the broadcast signal while the communication unit 21 of the mobile station device 20 is waiting to receive the broadcast signal in step S2, the communication unit 21 of the mobile station device 20 Then, broadcast signals are received from the base station devices 10-1 and 10-2 (step S4).

When the communication unit 21 of the mobile station device 20 receives the broadcast signal, the OTDOA calculation unit 22 receives the broadcast signal transmitted by the base station device 10-1 from the reception time of the broadcast signal transmitted by the base station device 10-2. Is subtracted to calculate the observation time difference (step S5).
When the OTDOA calculation unit 22 calculates the observation time difference, the communication unit 21 transmits the calculated observation time difference to the position information calculation device 30 via the base station device 10-1 (step S6).
The communication unit 31 of the position information calculation device 30 receives the observation time difference from the mobile station device 20 (step S7).

Further, the location information calculation device 30 calculates the round-trip propagation delay time in communication with the mobile station device 20 to the base station device 10-1 in accordance with the transmission of the observation time difference calculation command to the mobile station device 20 in step S1. A command is transmitted (step S8).
When the position information calculation device 30 transmits a round-trip propagation delay time calculation command, the communication unit 11 of the base station device 10-1 receives the calculation command (step S9).

When the communication unit 11 of the base station device 10-1 receives the round-trip propagation delay time calculation command, the RTT measurement unit 12 of the base station device 10-1 performs the communication between the mobile station device 20 and the base station device 10-1. The round trip propagation delay time is measured (step S10). The measurement of the round-trip propagation delay time is not described in detail here because it is known in the standard or the like.
When the RTT measurement unit 12 measures the round-trip propagation delay time, the communication unit 11 transmits the measured round-trip propagation delay time to the position information calculation device 30 (step S11).
The communication unit 31 of the position information calculation device 30 receives the round trip propagation delay time from the base station device 10-1 (step S12).

When the communication unit 31 of the position information calculation device 30 receives the observation time difference in step S7 and receives the round trip propagation delay time in step S12, the correction value calculation unit 32 is based on the received observation time difference and round trip propagation delay time. Then, the correction value of the base station 10-2 is calculated (step S13). The details of the correction value calculation method will be described later.
When the correction value calculation unit 32 calculates the correction value of the base station 10-2, the correction value registration unit 33 stores the correction value storage unit 34 in association with the cell ID (cell B) indicating the base station 10-2. The calculated correction value is registered in the correction value table (step S14).
The correction value of the base station 10-3 can also be calculated using a similar method.

Next, a correction value calculation method by the correction value calculation unit 32 will be described.
Correction value _{z 2} of the base station 10-2 is calculated using equation (4).

Here, s indicates the speed of light. Moreover, OTDOA _{(1, 2)} indicates the observation time difference received by the communication unit 31 in step S7. D _(1,2) represents the distance between the base station apparatus 10-1 and the base station apparatus 10-2. RTT ₁ indicates the round-trip propagation delay time received by the communication unit 31 in step S12.
The distance D _{(1, 2)} can be calculated by the equation (5) based on the coordinates of the base station devices 10-1 and 10-2 stored in the correction value table stored in the correction value storage unit 34.

However, the coordinates XA, XB, YA, YB indicate the coordinates of the base station apparatuses 10-1, 10-2 stored in the correction value table stored in the correction value storage unit 34.

Here, explaining why the z ₂ calculated by equation (4) becomes the correction value.
FIG. 6 described above is a diagram showing a geographical arrangement of the base station apparatus and the mobile station apparatus.
In the equation (4), first, the observation time difference OTDOA _{(1, 2)} is multiplied by the speed of light s, and the absolute value thereof is obtained, whereby the distance between the base station apparatus 10-1 and the mobile station apparatus 20 is A distance represented by a difference between the distance between the station device 10-2 and the mobile station device 20 is calculated.
That is, referring to FIG. 6, the point where the base station device 10-1 exists is point A, the point where the base station device 10-2 exists is point B, and the point where the mobile station device 20 exists is point C. The difference between the distance between the points AP and the distance between the points BP is calculated.
However, since the distance difference calculated here includes an error due to a feeder length from the radio output of the base station apparatus to the antenna and a propagation time when the radio unit is remotely installed, d shown in FIG. Instead, it is the value of d ′.

In Expression (4), the value obtained by multiplying the round-trip propagation delay time RTT ₁ by the light velocity s is divided by 2, and the value is subtracted from the distance D _{(1, 2)} .
A value obtained by multiplying the round-trip propagation delay time RTT ₁ by the light velocity s indicates a round-trip transmission distance of data between the mobile station apparatus 20 and the base station apparatus 10-1. That is, referring to FIG. 6, the distance between the points APA is shown. Therefore, the distance R between the points AP can be calculated by dividing the round trip distance by 2.

When the mobile station device 20 exists at a point distant from the point A by the distance R, the difference d between the distance between the points AP and the distance between the points BP is D−R ≦ d ≦ D. Therefore, even if it is assumed that the distance difference d of the mobile station apparatus 20 located in a minute cell is D−R, the error can be suppressed to a minute distance R or less. Further, even if the distance R is not calculated, by using a small cell radius as R, the error can be suppressed to a small radius R or less.
Therefore, a difference d ′ between the distance between the points AP including the error and the distance between the points BP and a value obtained by subtracting the distance R (or a minute cell radius) between the points AP from the distance D between the points AB. By calculating the difference, it is possible to calculate a correction value for correcting the error in the calculated distance due to the propagation delay of the signal to the antenna in the base station apparatus 10-2.

Next, an operation in which the position information calculation system calculates the position information of the mobile station device 20 will be described.
FIG. 5 is a second sequence diagram illustrating the operation of the position information calculation system.
When the mobile station device 20 is located in the base station device 10-1, the communication unit 31 of the position information calculation device 30 communicates with the mobile station device 20 via the base station device 10-1. 1 and an instruction for calculating an observation time difference between the base station apparatus 10-2 and an observation time difference between the base station apparatus 10-1 and the base station apparatus 10-3 are transmitted (step S21).
When the position information calculation device 30 transmits an observation time difference calculation command, the communication unit 21 of the mobile station device 20 receives the calculation command (step S22).
Upon receiving the observation time difference calculation command, the communication unit 21 of the mobile station device 20 waits for reception of broadcast signals from the base station devices 10-1, 10-2, and 10-3.

The communication units 11 of the base station apparatuses 10-1, 10-2, and 10-3 are synchronized with each other, and transmit broadcast signals at the same time, periodically or in accordance with instructions from the position information calculation apparatus 30 (steps). S23).
When the base station devices 10-1, 10-2, and 10-3 transmit the broadcast signal while the communication unit 21 of the mobile station device 20 is waiting to receive the broadcast signal in step S22, the mobile station device 20 The communication unit 21 receives broadcast signals from the base station devices 10-1, 10-2, 10-3 (step S24).

When the communication unit 21 of the mobile station device 20 receives the broadcast signal, the OTDOA calculation unit 22 determines the observation time difference between the base station device 10-1 and the base station device 10-2, and the base station device 10-1 and the base station device. An observation time difference from 10-3 is calculated (step S25).
When the OTDOA calculation unit 22 calculates the observation time difference, the communication unit 21 transmits the calculated observation time difference to the position information calculation device 30 via the base station device 10-1 (step S26).
The communication unit 31 of the position information calculation device 30 receives the observation time difference from the mobile station device 20 (step S27).

When the communication unit 31 receives the observation time difference, the position information calculation unit 35 acquires the correction values of the base station apparatuses 10-1, 10-2, and 10-3 from the correction value table stored in the correction value storage unit 34 ( Step S28).
When the position information calculation unit 35 acquires the correction value, the position information calculation unit 35 calculates the position information of the mobile station device 20 (step S29).
The calculated location information may be transmitted to the mobile station device 20 and provided as current location information, or may be used for cell management of the corresponding base station device. Further, for example, the position information may be used for specifying the transmission position of the reporter of the police report phone.

Next, a method for calculating position information by the position information calculation unit 35 will be described.
First, the position information calculation unit 35 calculates a distance d represented by the difference between the distance between the points AP and the distance between the points BP. The distance d can be calculated by equation (6).

However, z ₁ indicates the correction value of the base station apparatus 10-1, and z ₂ indicates the correction value of the base station apparatus 10-2.
The absolute value of s · OTDOA _{(1, 2)} indicates the distance d ′ shown in FIG. 6, and the error is canceled by the correction values of the base station apparatuses 10-1 and 10-2 with respect to d ′. The distance d can be obtained.

When calculating the distance d, the position information calculation unit 35 calculates the coefficient a by the equation (2) and calculates the coefficient b by the equation (3). Next, using the calculated coefficients a and b, a function of a hyperbola H that passes through the point P where the mobile station device 20 exists is derived by the equation (1).
Similarly, by measuring an observation time difference between a set of other base station apparatuses, deriving a function of a hyperbola H ′ where the observation time difference is constant, and calculating an intersection of the hyperbola H and the hyperbola H ′, the mobile station The point P where the device exists is obtained.

As described above, according to the present embodiment, the position information calculation device 30 includes the base station devices 10-1 to 10-10 stored in the observation time difference in the mobile station device 20 and the correction value table stored in the correction value storage unit 34. Based on the respective correction values of −3, position information of the mobile station apparatus is calculated. Thereby, it is possible to correct the observation time difference in the mobile station apparatus and calculate accurate position information.

As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the scope of the present invention. It is possible to
For example, in the present embodiment, the case where the number of base station apparatuses is three has been described. However, the present invention is not limited to this, and the position information calculation system may include four or more base station apparatuses.

In the present embodiment, the case has been described in which the correction values of the other base station apparatuses 10-2 and 10-3 are obtained using the base station apparatus 10-1 having a minute cell and the correction value of 0. For example, the base station device 10-2 for which the correction value is calculated by the base station device 10-1 and the mobile station device 20 that is known to have a small distance R from the base station device 10-2. The correction value of the base station apparatus 10-3 may be obtained by using it.

Further, in the present embodiment, the case where the position information is calculated using the base station apparatus 10-1 used for calculating the correction value is not limited to this. For example, the base station apparatus 10-1 is not used. In addition, the position information may be calculated using the base station apparatuses 10-2 and 10-3 and another base station apparatus 10-4.

Further, in the present embodiment, the case where the position information is calculated by obtaining the intersection of two hyperbolic curves has been described. However, the present invention is not limited to this. For example, the position information may be calculated using a plurality of three or more hyperbolic curves. good. At this time, it is assumed that not all hyperbola intersect at one point due to an error. In this case, the center position of the intersection of each hyperbola is calculated, and the position may be set as the position P of the mobile station apparatus.

Further, in the present embodiment, the correction value of the base station apparatus 10-2 is calculated only once and the position information is calculated using the correction value. For example, the correction value is calculated a plurality of times and calculated. By taking an average of the corrected values, a more accurate correction value can be calculated. At this time, it is better to calculate the correction value using a plurality of base station apparatuses.
For example, when obtaining the correction value of the base station device 10-3, the correction value is first calculated from the observation time difference between the base station device 10-1 and the base station device 10-3, and then the base station device 10-2 and the base station device 10-3. A correction value is calculated based on the observation time difference of the station apparatus 10-3, and the average is calculated. Further, when calculating the average value, it is better to perform weighting according to the cell size.

In the present embodiment, the base station apparatus 10-1 includes the RTT measurement unit 12, and the correction value is calculated based on the round-trip propagation delay time measured by the RTT measurement unit 12. However, the present invention is not limited to this. For example, the base station apparatus 10-1 may be configured not to include the RTT measurement unit 12 by calculating a correction value using a small cell radius instead of the round-trip propagation delay time.

In the present embodiment, the base station apparatus 10-1 includes the RTT measurement unit 12, and the correction value is calculated based on the round-trip propagation delay time measured by the RTT measurement unit 12. However, the present invention is not limited to this. For example, the mobile station device 20 may include an RTT measurement unit, and the correction value may be calculated based on the round-trip propagation delay time measured by the RTT measurement unit of the mobile station device 20.

The position information calculation device 30 described above has a computer system therein. The operation of each processing unit described above is stored in a computer-readable recording medium in the form of a program, and the above processing is performed by the computer reading and executing this program.
Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like.
Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

Further, the program may be for realizing a part of the above-described functions. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

According to the present invention, the position information calculation device calculates the position information of the mobile station device based on the observation time difference in the mobile station device and the correction value stored in the correction value storage means. Thereby, it is possible to correct the observation time difference in the mobile station apparatus and calculate accurate position information.

10-1 to 10-3: Base station device 11: Communication unit 12 ... RTT measurement unit 20 ... Mobile station device 21 ... Communication unit 22 ... OTDOA calculation unit 30 ... Location information calculation device 31 ... Communication unit 32 ... Correction value calculation unit 33 ... Correction value registration unit 34 ... Correction value storage unit 35 ... Position information calculation unit

Claims (11)

A location information calculation system comprising a plurality of base station devices and a location information calculation device that calculates location information of a mobile station device,
Each base station apparatus includes a synchronous transmission unit that transmits a signal to the mobile station apparatus via an antenna at the same time as other base station apparatuses,
The mobile station device
Receiving means for receiving signals transmitted synchronously from the two base station devices;
An observation time difference calculating means for calculating an observation time difference between two signals received by the receiving means;
Observation time difference transmission means for transmitting the observation time difference calculated by the observation time difference calculation means to the position information calculation device;
With
The position information calculation device includes:
Correction value storage means for storing a correction value used for correcting an error of the observation time difference calculated by the observation time difference calculation means of the mobile station apparatus in association with base station apparatus identification information indicating each of the plurality of base station apparatuses. The error is a correction value storage means that is generated by a propagation time until the signal transmitted by the synchronous transmission means of the base station apparatus reaches the antenna of the base station apparatus;
Observation time difference receiving means for receiving the observation time difference from the mobile station device;
Position information calculating means for calculating position information of the mobile station apparatus based on the observation time difference received by the observation time difference receiving means and the correction value stored by the correction value storage means;
A position information calculation system comprising: Either the mobile station apparatus and the base station apparatus in which the mobile station apparatus is located are:
Round-trip propagation delay time measuring means for measuring round-trip propagation delay time between antennas of the mobile station device and the base station device;
Round-trip propagation delay time transmitting means for transmitting the round-trip propagation delay time measured by the round-trip propagation delay time measuring means to the position information calculating device;
With
The position information calculation device includes:
Round-trip propagation delay time receiving means for receiving the round-trip propagation delay time from the round-trip propagation delay time transmitting means;
Correction value calculating means for calculating the correction value based on the observation time difference received by the observation time difference receiving means and the round trip propagation delay time received by the round trip propagation delay time receiving means;
Correction value registration means for registering the correction value calculated by the correction value calculation means in the correction value storage means;
The position information calculation system according to claim 1, further comprising: The correction value storage means of the position information calculation device stores at least a correction value associated with base station device identification information indicating a first base station device that is one of the plurality of base station devices. ,
An observation time difference between the first base station apparatus and the second base station apparatus, which is a base station apparatus different from the first base station apparatus, from the mobile station apparatus by the observation time difference receiving means of the position information calculation apparatus And when the round trip propagation delay time receiving means receives the round trip propagation delay time between the mobile station apparatus and the first base station apparatus from the round trip propagation delay time transmitting means, the correction value calculating means Z ₂ indicating the correction value of the second base station device, s indicating the light velocity, and the observation time difference between the first base station device and the second base station device in the mobile station device. OTDOA _(1,2) , D _(1,2) indicating the distance between the first base station device and the second base station device, the mobile station device and the first base station device RTT ₁ indicating the round-trip propagation delay time between

To calculate the correction value of the second base station device from
The position information calculation system according to claim 2. The propagation time until the signal transmitted by the synchronous transmission means of the first base station apparatus reaches the antenna of the first base station apparatus is small enough to be ignored,
The correction value storage means of the position information calculation device stores zero as a correction value associated with base station device identification information indicating the first base station device.
The position information calculation system according to claim 3. The observation time difference calculation means of the mobile station device calculates a difference in signal observation time between the two base station devices from two or more sets of the base station devices,
The location information calculation means of the location information calculation device acquires a correction value of each base station device constituting a set of base station devices from which the mobile station device has calculated the observation time difference,
D indicating the difference in distance from each base station device of the set of base station devices to the mobile station device, s indicating the speed of light, and the observation time difference of the signal from the set of base station devices in the mobile station device. OTDOA shown, correction value z _{1 of} the base station device in which the mobile station device is in the set of base station devices, and the mobile station device is not in the set of base station devices Using the correction value z ₂ of the other base station device,

The distance difference d is calculated from
A hyperbola function focusing on the position of the base station device based on the distance difference is calculated for each of the set of base station devices, and an intersection of the calculated hyperbolic functions is calculated as position information of the mobile station device.
The position information calculation system according to claim 3. A location information calculation method using a location information calculation system comprising a plurality of base station devices and a location information calculation device that calculates location information of a mobile station device,
The synchronous transmission means of each base station device transmits a signal to the mobile station device via an antenna at the same time as other base station devices,
The receiving means of the mobile station apparatus receives signals transmitted synchronously from the two base station apparatuses,
The observation time difference calculating means of the mobile station device calculates an observation time difference between the two signals received by the receiving means,
The observation time difference transmission means of the mobile station device transmits the observation time difference calculated by the observation time difference calculation means to the position information calculation device,
The observation time difference receiving means of the position information calculation device receives the observation time difference from the mobile station device,
The position information calculation means of the position information calculation apparatus is configured to propagate the observation time difference received by the observation time difference reception means and the signal transmitted by the synchronous transmission means of the base station apparatus until reaching the antenna of the base station apparatus. Calculating position information of the mobile station device based on a correction value used for correcting the error of the observation time difference, which is generated by time,
The positional information calculation method characterized by the above. A location information calculation device that calculates location information of the mobile station device based on received signals from a plurality of base station devices in the mobile station device,
Correction value storage means for storing a correction value used for correcting an error of the observation time difference calculated by the observation time difference calculation means of the mobile station apparatus in association with base station apparatus identification information indicating each of the plurality of base station apparatuses. The error is a correction value storage means that is generated by a propagation time until the signal transmitted by the synchronous transmission means of the base station apparatus reaches the antenna of the base station apparatus;
An observation time difference receiving means for receiving an observation time difference of signals for a set of two base station devices from the mobile station device;
Position information calculating means for calculating position information of the mobile station apparatus based on the observation time difference received by the observation time difference receiving means and the correction value stored by the correction value storage means;
A position information calculation device comprising: A location information calculation device that calculates location information of the mobile station device based on signals received from a plurality of base station devices by the mobile station device,
Correction value storage means for storing a correction value used for correcting an error of the observation time difference calculated by the observation time difference calculation means of the mobile station apparatus in association with base station apparatus identification information indicating each of the plurality of base station apparatuses. And the error is a correction value storage means that is generated by a propagation time until the signal transmitted by the synchronous transmission means of the base station apparatus reaches the antenna of the base station apparatus,
An observation time difference receiving means for receiving, from the mobile station device, a signal observation time difference for a set of two base station devices;
Position information calculating means for calculating position information of the mobile station device based on the observation time difference received by the observation time difference receiving means and the correction value stored by the correction value storage means;
Program to operate as. Due to the propagation time until the signal transmitted by each of the plurality of base station apparatuses reaches the antenna of the base station apparatus, the difference in observation time between the signals transmitted synchronously from the two base station apparatuses received by the mobile station apparatus A correction value calculation device that calculates a correction value used for correcting an error that occurs,
Observation time difference receiving means for receiving the observation time difference from the mobile station device;
The round-trip propagation delay time between antennas of the mobile station device and the base station device is determined from the mobile station device and the round-trip propagation delay time transmission means of the base station device where the mobile station device is located. A round-trip propagation delay time receiving means for receiving;
Correction value calculating means for calculating the correction value based on the observation time difference received by the observation time difference receiving means and the round trip propagation delay time received by the round trip propagation delay time receiving means;
A correction value calculation device comprising: Included in a location information calculation device that calculates location information of the mobile station device,
The correction value storage means of the position information calculation device stores at least a correction value associated with base station device identification information indicating a first base station device that is one of the plurality of base station devices. ,
The observation time difference receiving means receives from the mobile station device an observation time difference between the first base station device and a second base station device that is a base station device different from the first base station device; When the round-trip propagation delay time receiving means receives the round-trip propagation delay time between the mobile station apparatus and the first base station apparatus from the round-trip propagation delay time transmitting means, the correction value calculating means Z ₂ indicating the correction value of the base station apparatus, s indicating the light velocity, OTDOA _(1, indicating the signal observation time difference between the first base station apparatus and the second base station apparatus in the mobile station apparatus ₂₎ D _(1,2) indicating the distance between the first base station apparatus and the second base station apparatus, and round-trip propagation between the mobile station apparatus and the first base station apparatus Using RTT ₁ indicating the delay time,

To calculate the correction value of the second base station device from
The correction value calculation apparatus according to claim 9. Due to the propagation time until the signal transmitted by each of the plurality of base station apparatuses reaches the antenna of the base station apparatus, the difference in observation time between the signals transmitted synchronously from the two base station apparatuses received by the mobile station apparatus A correction value calculation device that calculates a correction value used to correct an error that occurs,
Observation time difference receiving means for receiving the observation time difference from the mobile station device;
Round-trip propagation delay time reception for receiving round-trip propagation delay time between the mobile station apparatus and the base station apparatus from either the mobile station apparatus or the base station apparatus in which the mobile station apparatus is located means,
Correction value calculating means for calculating the correction value based on the observation time difference received by the observation time difference receiving means and the round trip propagation delay time received by the round trip propagation delay time receiving means;
A program that runs as

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