KR101634126B1 - method, apparatus, and recording medium for estimating location - Google Patents

Abstract

The present invention relates to a method and an apparatus for estimating a position. More particularly, to a fingerprinting method for estimating a position of a specific terminal based on signal strength and a method and an apparatus for estimating a position using a PDR method using an inertial measurement device. In particular, the present invention relates to a position estimation apparatus for estimating a reception position of a reference signal received from each of a position prediction unit for calculating a predicted position based on previous position information and movement information received from an inertia measurement apparatus, A position estimator for calculating an estimated position based on radio map information in which a reference reception strength of each of the received reference signals is stored for each of a plurality of reference points and conversion matrix information for correcting reception strength of a reference signal, A final position determining unit for calculating a current position of the terminal based on the position and the estimated position, and a conversion matrix calculating unit for calculating the next conversion matrix information used for the next position estimation of the terminal, Lt; / RTI >

Description

[0001] The present invention relates to a position estimation method, an apparatus and a recording medium therefor,

The present invention relates to a method and an apparatus for estimating a position. More particularly, to a fingerprinting method for estimating a position of a specific terminal based on signal strength and a method and an apparatus for estimating a position using a PDR method using an inertial measurement device.

Recently, various mobile devices with improved portability such as smart phones and tablet PCs are increasing, and new service models such as various business models and social networks that provide services based on user's location are being developed.

In order to measure the current position of the mobile device in such a situation, a variety of position estimation techniques such as GPS position estimation or triangulation using a specific signal are being studied.

However, in the case of the technique of estimating the position by receiving the GPS signal, it is difficult to estimate the precise position of the device since it is difficult to receive the satellite signal when the GPS signal is located inside the building or between the high-rise buildings.

Particularly, as the importance of position estimation in an indoor situation such as a building is increasing, a technique for indoor position estimation is required. For example, a fingerprinting technique for estimating a position by comparing information on the strength of a signal transmitted from a transmitter and a received signal received from each point with stored signal map information has been studied.

However, in the case of such a fingerprinting technique, when there is a change in the surrounding environment between the time of constructing the signal map and the time when the actual terminal device receives the signal and estimates the position thereof, the path of the signal changes, There is a problem. In addition, there is a possibility that the strength of the received signal may vary depending on the type and direction of the terminal device, and thus the reliability of the position estimation is lowered. That is, in the fingerprinting method, there is a problem that the accuracy of the position estimation is lowered in accordance with the variation factor of the signal intensity.

Also, in the case of the position estimation method using the inertial measurement unit (IMU), there is a problem that the accuracy of the position estimation is significantly lowered over time due to accumulation of the error.

The present invention, which is devised to solve the above-described problems, provides an apparatus and method for determining a final position of a terminal using a position estimation value of a fingerprinting scheme using movement information of a terminal using an inertia measurement device and a reference signal reception strength .

Also, the present invention provides a position estimation apparatus and method for further improving a position estimation accuracy of a fingerprinting scheme using a correction conversion matrix value that takes into consideration that a reference signal reception intensity is changed according to a surrounding environment.

The present invention also provides an apparatus and method for continuously calculating a transformation matrix at a next time point to provide a more accurate next transformation matrix.

According to an aspect of the present invention, there is provided a terminal for calculating a position, comprising: a position predicting unit for calculating a predicted position based on previous positional information and movement information received from an inertial measurement apparatus; A radio map information storing a reference reception strength of each of the plurality of reference points received at the plurality of reference points and a conversion matrix information for correcting the reception intensity of the reference signal, A final position determination unit for calculating a current position of the terminal based on the predicted position and the estimated position, and a conversion matrix calculation unit for calculating the next conversion matrix information used for the next position estimation of the terminal And a terminal unit.

According to another aspect of the present invention, there is provided a method of calculating a position of a terminal, the method comprising: a position estimation step of calculating a predicted position based on previous position information and movement information received from the inertial measurement device; Based on the reception intensity, the radio map information in which the reference reception intensities of the reference signals received at the plurality of reference points are stored for each of a plurality of reference points, and the conversion matrix information for correcting the reception intensities of the reference signals, A final position determination step of calculating a current position of the terminal based on the predicted position and the estimated position, and a conversion matrix calculation step of calculating a next transformation matrix information used for the next position estimation of the terminal .

According to another aspect of the present invention, there is provided a recording medium on which a program for executing a method for calculating a position of a terminal is recorded. The recording medium includes a position estimation function for calculating a predicted position based on previous positional information and movement information received from the inertial measurement device, The reception intensity of the reference signal received from each of the signal transmission apparatuses, the radio map information in which the reference reception intensities of the reference signals received at the plurality of reference points are stored for each of a plurality of reference points, A final position determination function for calculating the current position of the terminal based on the predicted position and the estimated position, and the next transformation matrix information used for the next position estimation of the terminal, A program that implements the transform matrix calculation function to be computed is recorded and read by a computer Thereby providing a recording medium.

According to the present invention described above, the final position of the terminal is determined by using the position estimation value of the fingerprinting method using the movement information of the terminal using the inertial measurement device and the reference signal reception intensity.

In addition, the present invention provides an effect of further improving the accuracy of position estimation of the fingerprinting scheme by using the correction conversion matrix value that takes into consideration that the reference signal reception intensity is changed according to the surrounding environment.

Further, the present invention provides the effect of continuously calculating the transformation matrix at the next time point to provide a more accurate next transformation matrix.

1 is a diagram for explaining an error accumulation phenomenon in the case where a position of a terminal is estimated based on movement information received by the inertial measurement apparatus of the present invention.
2 is a diagram for explaining a fingerprinting positioning method that can be used in the present invention.
3 is a view for explaining an error of a reference signal reception intensity of a fingerprinting positioning method that can be used in the present invention.
4 is a diagram illustrating a configuration of a terminal according to an embodiment of the present invention.
5 is a view for explaining an estimated position calculating method according to another embodiment of the present invention.
6 is a view for explaining an operation of calculating a current position using a measurement position and an estimated position according to another embodiment of the present invention.
FIG. 7 is a diagram illustrating a next transformation matrix information calculation operation according to another embodiment of the present invention.
8 is a view for explaining calculation of the next conversion matrix information according to another embodiment of the present invention.
9 is a diagram illustrating an operation of calculating a next transformation matrix at an initial position according to another embodiment of the present invention.
10 is a diagram illustrating a position estimation method according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference numerals whenever possible, even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Additional aspects of the invention will become apparent through the following examples. The terms used in this specification are terms selected in consideration of functions in the embodiments, and the meaning of the terms may vary depending on the user, the intention or custom of the operator, and the like. Therefore, the meaning of the terms used in the following embodiments is defined according to the definition when specifically defined in this specification, and unless otherwise defined, it should be interpreted in a sense generally recognized by those skilled in the art.

In addition, the configurations of the selectively described embodiments or selectively described embodiments of the present invention may be combined with each other in a single integrated configuration, if they are not obviously technically contradictory to the ordinary artisan unless otherwise stated. It should be understood that

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected,""coupled," or "connected."

The present invention relates to a method of estimating a position of a terminal and a position estimating apparatus.

There are various methods for estimating the position of the mobile terminal. For example, it may be estimated using a satellite positioning system such as GPS. However, the accuracy of the position estimation using the satellite is very low when there is a problem in reaching the satellite signal between the high-rise buildings or the indoor environment. Accordingly, the present invention relates to a method and an apparatus for estimating a position of a terminal based on a reception strength of a reference signal transmitted by a transmitting apparatus, rather than a satellite signal, and movement information measured from the inertial measurement apparatus.

In addition, the present invention provides a method of correcting the reception strength of a reference signal using a transformation matrix to improve positional accuracy of a terminal. Through this, it is possible to accurately estimate the position of the terminal even in a situation where it is not assisted by a satellite navigation apparatus such as GPS.

Hereinafter, a method of estimating a position of a mobile station based on movement information received from an inertial measurement apparatus that can be used in the present invention, and a method of estimating a position using a wireless map by receiving a reference signal will be described.

1 is a diagram for explaining an error accumulation phenomenon in the case where a position of a terminal is estimated based on movement information received by the inertial measurement apparatus of the present invention.

The terminal of the present invention can estimate a position using a pedestrian dead reckoning (hereinafter referred to as PDR) positioning method using an inertial measurement unit (IMU).

The PDR-based positioning method refers to a method of determining a moving speed, a moving direction, and moving distance information of a terminal by using various sensors including an inertia measuring device, and calculating a relative position from a starting point. In the case of the PDR system, both indoor and outdoor positioning are possible, and various sensors mounted on the terminal can be utilized. However, there is a problem in that when the position of the mobile station is continuously estimated and tracked using the PDR scheme, an accumulated error due to the positioning error of the sensor occurs.

Referring to FIG. 1, it is assumed that the terminal moves from the initial position 110 to 112, 114, and 116 to the final 118 position. And estimates the position of the terminal based on the movement information received from the inertial measurement device, which may be included in the terminal, when the terminal performs position estimation in the PDR scheme. For example, when the terminal moves from the initial position 110 to the point 112, it can estimate the moving position of the terminal based on the moving direction information and the moving distance information of the terminal. However, the information received from the inertial measurement apparatus may have a certain error, and the position of the terminal can be measured to 152 points when the terminal is located at the 112 point according to the error. In the case of the PDR scheme, when estimating the next location of the mobile station, the mobile station estimates the location according to the movement information based on the previous location. Accordingly, when the mobile station moves from the location 112 to the location 114, The following location can be estimated.

However, as shown in FIG. 1, the difference between the 152 points estimated by the terminal and the 112 point, which is the location of the actual terminal due to the error, may occur at a certain level. Here, when the terminal moves to point 114, the terminal estimates the next position based on the estimated movement 152 based on the movement information. In this case, an error may also occur and the position can be estimated to 154 points. In this way, when the mobile station continuously moves, the error accumulation problem of the inertial measurement apparatus and the problem that the next position is misdetected when the reference position is deviated can cause the estimated position of the mobile station to be continuously inaccurate. For example, the terminal may be determined to have moved from point 110 to point 152, point 152 to point 154, and point 156. Therefore, the estimated location of the end terminal can be estimated at 158 points, which can be considerably different from the actual location of the terminal at 118 points.

Although FIG. 1 illustrates a relatively large error in order to better explain the problem, in the case where the location tracking of the terminal is continuously performed due to the characteristic of the PDR scheme even if a minute error occurs, the error Can be continuously increased. Therefore, a position estimation method for solving the problem of the PDR scheme is required.

The position estimation method and apparatus of the present invention proposes a position estimation method combining a fingerprinting method to solve the position estimation problem of the PDR method described above.

The terminal of the present invention can further estimate the position using the fingerprinting positioning method. The fingerprinting method is a method of estimating the position of the terminal using the strength of the measured signal. Specifically, a method of estimating a position of a terminal using a point having a similar signal strength value by comparing a signal strength received by a terminal with a wireless map, which is a result of measuring signal strength at a plurality of reference points. However, the fingerprinting method has a problem that the signal strength can be changed when the wireless map is generated and when the surrounding environment is changed, and the accurate position can not be estimated when the signal strength is changed. In order to solve these problems, the present invention will be described in detail with reference to FIG.

2 is a diagram for explaining a fingerprinting positioning method that can be used in the present invention.

A method of estimating the position of the terminal 200 using the fingerprinting method described above with reference to FIG. 2 will be described. The fingerprint technique is a method of estimating a position using a received signal reference reception strength information collected at a predetermined position in a service area by arbitrarily selecting a plurality of positions. Herein, the selected position is referred to as a reference point or a reference position (210 to 230, hereinafter referred to as a reference point), and the positioning accuracy of the fingerprint technique tends to improve as a large number of reference points 210 to 230 are densely arranged . In order to show the same level of positioning accuracy as the trilateration method in which only the distance information affects the current position determination, many reference points (210 to 230) must be uniformly selected in a wide service area in the preliminary information gathering step. The terminal 200 receives the reference signal transmitted from one or more transmission apparatuses and compares the reception intensity of the received reference signal with the reference signal reception intensity of each transmission apparatus previously measured and stored at the reference points 210 to 230 The location of the terminal can be estimated using a point having a similar reception strength.

For example, the terminal 200 can receive reference signals from four access points (APs), respectively. The received signal strength (RSS) of each received reference signal may be -14 for AP1, -10 for AP2, -20 for AP3, and -30 for AP4. The terminal or the wireless network compares the reception strength of each of the received reference signals with the reference reception strength of each of the reference signals at the plurality of reference points. That is, the wireless map measures and stores the reference reception strength of the reference signal transmitted from each of the transmission apparatuses at the reference points 210 to 230 in advance. In FIG. 2, it can be seen that the reception strength of the reference signals transmitted from the 220 reference points and 230 reference points and the respective transmission apparatuses of the terminal 200 is similar. It is also found that the reception strength of the reference signal at the 230 reference point is the same. Accordingly, the terminal 200 can estimate its position by being located at the reference point 230 having the same reference signal reception strength.

However, in such a fingerprinting method, when the wireless map information storing the reference reception strength of the reference signal is stored at a plurality of reference points, and at the time when the current terminal desires to estimate the position using the reference signal, Errors may occur due to variations. Also, it may be difficult to estimate the accurate position due to the problem that the reception strength of the reference signal is measured differently for each terminal.

3 is a view for explaining an error of a reference signal reception intensity of a fingerprinting positioning method that can be used in the present invention.

Referring to FIG. 3, there may be a difference between reference signal reception strength values and reference signal reception strength values depending on the difference between reference signal reception strengths and reception timing of reference signals. The X axis represents the reception intensity of the reference signal received by the terminal and the Y axis represents the cumulative density function value. In addition, the measurement data (a) (Measured data a) shows the distribution of the reception strength of the reference signal measured by the terminal 1 at the first time. That is, the reception strength of the reference signal measured by the terminal 1 at the first time point can be measured as shown in the graph 310. The measurement data b (Measured data b) shows the distribution of the reception strength of the reference signal measured by the terminal 2 at the first time point. That is, the reception strength of the reference signal measured by the terminal 2 at the first time point can be measured as shown in the 320 graph. The terminal 1 and the terminal 2 measure the reception strength of the reference signal at the same point at the same point, and a difference may occur as shown in FIG. 3 depending on the characteristics of the terminal. That is, even if a reference signal is received at the same point in the same point in the case of using the fingerprinting method, an error may occur according to signal reception characteristics of each terminal.

On the other hand, the measurement data c (Measured data c) shows the distribution of the reception strength of the reference signal measured by the terminal 2 at the second time point. That is, the reception strength of the reference signal measured by the terminal 2 at the second time point can be measured as 330 graph. That is, although the reception strength of the reference signal is received at the same point using the same terminal 2 as the measurement data (b), a difference may occur when the point of time changes. Therefore, even if the fingerprinting method is employed, there is a problem that the reception intensity of the reference signal received at the same point may change when the viewpoint changes.

The generation of the error may be caused by a difference in signal reception characteristics such as the antenna arrangement of each terminal, a change in the surrounding environment depending on the point of time, and the like. Therefore, the method of estimating the position of the terminal using only the fingerprinting method, May occur.

Accordingly, the present invention provides a positioning method that can improve accuracy by solving the above-mentioned problems. The present invention provides a method of using a transformation matrix for correcting reference signal reception intensity information in estimating a position according to a fingerprinting scheme. In addition, the present invention provides a method of fusing predicted position information predicted according to the PDR scheme with an estimated position estimated by a fingerprinting method in order to further improve the accuracy of the positioning method.

A detailed description of the present invention will be given by way of example with reference to the drawings.

4 is a diagram illustrating a configuration of a terminal according to an embodiment of the present invention.

A terminal for calculating a position according to an embodiment of the present invention includes a position predicting unit 410 for calculating a predicted position based on previous position information and movement information received from the inertial measurement apparatus, A radio map information storing a reference reception strength of each of the plurality of reference points received at the plurality of reference points and a conversion matrix information for correcting the reception intensity of the reference signal, A final position determiner 430 for calculating a current position of the terminal based on the predicted position and the estimated position, and a next transformation matrix information And a transform matrix calculator 440 for calculating a transform matrix.

Referring to FIG. 4, the terminal may include a position predicting unit 410 for calculating a predicted position based on previous positional information and movement information received from the inertial measurement apparatus. The previous location information means an estimated location before estimating the current location of the terminal. For example, in estimating the position of the UE at time t = 2, the previous position may be the position of the UE at time t = 1. Alternatively, the previous location may refer to the location of the terminal ultimately estimated before time t = 2.

The position predicting unit 410 may calculate the predicted position using the previous position information as a reference point and using at least one of the moving speed information, the moving distance information, and the moving direction information included in the moving information. In one example, the movement information may be received from the inertial measurement device, and the received movement information includes information related to movement of the terminal. Specifically, when the previous position is the reference point, the current predicted position of the terminal can be calculated by receiving the direction movement direction information on which the terminal has moved and the movement distance information on the distance that the terminal has moved. That is, when the mobile station moves 20m in the south direction, the mobile station can calculate the predicted position by locating the mobile station 20m away from the previous position. In addition, the position predicting unit 410 may further receive the movement time information as the movement information. The moving distance can be calculated using the moving time information and the moving speed information, and the predicted position of the terminal can be calculated using the calculated moving distance information and moving direction information.

In other words, the position predicting unit 410 may calculate the predicted position using the pedestrian dead reckoning (PDR) algorithm described above.

For example, the predicted position can be calculated as follows by applying the PDR technique to the position predicting unit 410.

는 t 시점에서의 예측 위치를 나타내며, 이전 추정위치

와 관성 측정장치로부터 획득한 u_t의 합으로 계산할 수 있다. u_t는 수학식 2에 의해서 산출될 수 있다.In Equation (1)

Represents the predicted position at time t, and the previous estimated position

And u _t obtained from the inertial measurement device. u _t can be calculated by Equation (2).

That is, as in Equation (2), u _t can be derived using the movement distance? _T and the movement direction? _T information.

Meanwhile, the terminal may receive radio map information that stores the reception strength of the reference signal received from each of the one or more reference signal transmission apparatuses, the reference reception strength of each of the reference signals received at the plurality of reference points, And a position estimator 420 for calculating an estimated position based on the transformation matrix information for correcting the reception intensity of the reference signal.

The position estimating unit 420 may calculate the estimated position using the fingerprinting method based on the reception intensity of the received reference signal, the conversion matrix information, and the wireless map information. The wireless map information includes reference reception strength information of a reference signal received at a plurality of reference points as described above. Therefore, the position estimation unit 420 can estimate the position of the terminal based on the reference signal reception strength actually received at the terminal and the information of the wireless map. However, as described above, there is a problem that the reference signal reception strength at the same point is measured differently depending on the type of the terminal or when the reference signal is received.

In order to solve such a problem, the present invention uses transformation matrix information for correcting information of the reference signal reception intensity. The position estimating unit 420 may calculate the estimated position by correcting the reception intensity of the reference signal to the reference signal conversion reception intensity using the conversion matrix and comparing the reception intensity of the reference signal conversion with the wireless map information.

The position estimating unit 420 may calculate the estimated position based on the fingerprinting positioning algorithm based on the reference signal conversion reception intensity and the wireless map information. Specifically, for example, the position estimating unit 420 selects one or more reference points having high similarity in the wireless map using the reference signal converting reception intensity, and calculates an estimated position of the terminal using the position of the selected reference point can do. For example, the position estimator 420 may use a K-nearest neighbor (KNN) algorithm in selecting a reference point having a high degree of similarity. The KNN algorithm is an algorithm for deriving a geometric distance value by comparing the reception strength of the reference signal stored at each reference point of the wireless map with the reception strength of each reference signal received by the terminal.

Equation (1) is an equation showing an example of the KNN algorithm. Here, i denotes an index of a reference signal transmitting apparatus (AP), and j denotes an index of a reference point. Therefore, R _ji represents the reference signal reception strength of the j th transmission apparatus in the wireless map, and M _i represents the reference signal reception strength of the i th transmission apparatus measured by the terminal. Therefore, the Euclidean distance value converges to 0 when the reference signal reception strength of the specific transmission apparatus at the reference point is equal to the reference signal reception strength of the specific transmission apparatus measured by the terminal. Therefore, by using the KNN algorithm, the position of the terminal and the similarity of the reference point can be derived. That is, as the geometric distance value derived by the K-nearest neighbor (KNN) algorithm is smaller, the terminal can judge that the degree of similarity is high.

The location estimating unit 420 estimates the estimated location using the selected reference point. The location estimating unit 420 estimates the location using the average and variance of each reference point stored in the wireless map, (Minimum Mean Square Error) algorithm may be used.

As described above, the position estimating unit 420 may calculate the estimated position according to the fingerprinting positioning method using the reference signal converting reception intensity and the wireless map information. However, by using the transform matrix information in the case of the present invention, more precise position estimation can be performed because the reference signal conversion reception intensity considering changes in the surrounding environment or the characteristics of the terminal is used.

Meanwhile, the terminal may include a final position determination unit 430 for calculating the current position of the terminal based on the predicted position and the estimated position.

The final position determination unit 430 may calculate the current position of the terminal using the predicted position calculated by the position predictor 410 and the estimated position information calculated by the position estimator 420. [ For example, the final position determination unit 430 may calculate the current position by fusing the predicted position and the estimated position using a Kalman filter.

In addition, the terminal may include a transform matrix calculator 440 for calculating the next transform matrix information to be used for the next position estimation of the terminal.

The transform matrix calculator 440 calculates the next change matrix information used to estimate the position of the terminal at the next time point. For example, the transform matrix calculator 440 calculates the transform matrix using the transform matrix information used in the position estimator 420, the motion information used in the position predictor 410, the reference signal reception strength, The next transformation matrix information can be calculated using the intensity. The calculated next transformation matrix information can be used as a transformation matrix when calculating the estimated position at the next time point.

Accordingly, the transform matrix information is continuously updated, and the estimated position can be calculated using the more accurate transform matrix information.

The operation of each configuration of the present invention described with reference to FIG. 4 will be described below with reference to the drawings.

5 is a view for explaining an estimated position calculating method according to another embodiment of the present invention.

The position estimating unit according to another embodiment of the present invention may further include a position estimating unit for estimating a reception strength of the reference signal received from each of the one or more reference signal transmitting apparatuses, It is possible to calculate the estimated position based on the map (Radio Map) information and the conversion matrix information for correcting the reception strength of the reference signal.

Referring to FIG. 5, the position estimator receives a reference signal (S502). The reference signal may be a signal transmitted from a plurality of reference signal transmitting apparatuses, and the terminal may receive the reference signal and store the received signal strength of the reference signal for each transmitting apparatus. That is, the position estimating unit obtains the reference signal reception strength of each of the reference signals received at the plurality of reference points.

The position estimation unit may correct the received reference signal reception intensity information to the reference signal conversion reception intensity using the conversion matrix (S504). For example, the reception intensity of the reference signal can be corrected to the reference signal conversion reception intensity using the conversion matrix, and the estimated position can be calculated by comparing the reception intensity of the reference signal conversion with the wireless map information.

The position estimator may use Equation (4) to generate the reference signal conversion reception strength.

은 l 위치에서의 기준신호 변환 수신강도를 의미하며, H_t는 변환행렬 정보를 의미한다. 또한,

은 기준신호 수신강도를 의미한다. 따라서, 위치 추정부는 수학식 4를 이용하여 현재 t 시점에서의 기준신호 변환 수신강도를 생성함에 있어서, 변환행렬 정보와 기준신호 수신강도를 이용할 수 있다.

Denotes the reference signal conversion reception intensity at the l position, and H _t denotes the conversion matrix information. Also,

Denotes the reference signal reception strength. Therefore, the position estimating unit may use the transform matrix information and the reference signal reception strength in generating the reference signal transform reception intensities at the current time t using Equation (4).

Thereafter, the position estimator compares the generated reference signal conversion reception strength with the wireless map information (S506). In addition, the position estimator calculates the estimated position using the reference signal conversion reception intensity and the wireless map information according to the fingerprinting positioning method described above (S508).

As described above, the position estimating unit of the present invention calculates the estimated position using the reference signal conversion reception intensity generated using the transformation matrix, and calculates the estimated position based on the reception strength of the reference signal that can be measured differently depending on the surrounding environment and the determination time The estimated position can be calculated.

6 is a view for explaining an operation of calculating a current position using a measurement position and an estimated position according to another embodiment of the present invention.

A terminal according to another embodiment of the present invention may include a final position determination unit for calculating a current position of a terminal based on a predicted position and an estimated position.

6, the final position determination unit calculates the current position 600 of the terminal using the estimated position 601 calculated by the position prediction unit and the estimated position 605 calculated by the position estimation unit .

The predicted position 601 of the terminal means a point calculated by using the movement information as a reference point of the previous position 690 as described above.

In addition, the estimated position 605 of the terminal can be obtained by selecting the selected reference points 612, 613, and 618 using the reference signal conversion reception intensity at the plurality of reference points 610 to 624 included in the wireless map information . ≪ / RTI >

However, there is a difference between the predicted position 601 and the estimated position 605, so that a difference may occur. Accordingly, the final position determining unit can calculate the current position 600 using the predicted position 601 and the estimated position 605. [

For example, the final position determination unit may calculate the current position 600 of the UE using the predicted position 601 and the estimated position 605 and the Kalman filter algorithm. The final position determination unit calculates the Kalman gain using the covariance value of the predicted position 601 and the covariance value with respect to the estimated position 605 and calculates the Kalman gain using the predicted position 601, The current position 600 of the terminal can be calculated using the Kalman gain.

Specifically, a method of calculating the current position using the Kalman filter algorithm will be described as an example.

는 예측 위치의 예측 공분산 값을 나타내며, 이전 공분산 값과 위치 오차의 공분산 Q_t의 합으로 예측할 수 있다. 수학식 5를 이용하여 산출된 예측 위치의 공분산 값을 이용하여 이하 수학식을 통한 수식으로 현재 위치를 산출할 수 있다.In Equation (5)

Represents the predicted covariance value of the predicted position, and can be predicted as the sum of the previous covariance value and the covariance Q _t of the position error. The current position can be calculated using the following formula using the covariance value of the predicted position calculated using Equation (5).

K _t can be calculated as Equation (6) using Kalman gain, the predictive covariance value for the predicted position, and the covariance value R _t for the measured position error.

In addition, the covariance P _t and the current position at the current position can be calculated by the predicted position, the measured position information, and the Kalman gain.

는 산출하고자 하는 현재 위치를 의미하며,

는 예측 위치를 의미한다. 또한, K_t는 수학식 6에 의해서 산출되는 칼만 게인을 의미하며, Z_t는 추정 위치를 의미한다..In Equation (7)

Represents a current position to be calculated,

Indicates a predicted position. Further, K _t means the Kalman gain calculated by Equation (6), and Z _t means the estimated position.

)과 칼만 게인(K_t)을 이용하여 수학식 8과같이 산출될 수 있다. On the other hand, in order to calculate the current position at the next time, the covariance value (P _{t -1)} at the previous time is required as shown in Equation (5 ₎ . Therefore, it is necessary to calculate the covariance value (P _t ) at the current time point, which is the predicted covariance value (

) And a Kalman gain (K _t ), as shown in Equation (8).

As described above, the final position determining unit can calculate the current position based on the predicted position and the estimated position information using the Kalman filter algorithm.

Then, the terminal calculates the next transformation matrix information to be used at the next time point, thereby enabling accurate position tracking.

FIG. 7 is a diagram illustrating a next transformation matrix information calculation operation according to another embodiment of the present invention.

The UE according to another embodiment of the present invention may include a transform matrix calculation unit for calculating a next transform matrix information to be used for the next position estimation of the UE. The next transformation matrix information means information that can be used as transformation matrix information for calculating an estimated position at the next position.

Further, the conversion matrix calculator calculates the next conversion matrix information based on at least one of the movement information, the conversion matrix information, the received reference signal reception strength, and the reference signal reference reception strength estimated using the wireless map information at the current position .

Referring to FIG. 7, the transform matrix calculator may receive reference signal information (S702). The reference signal information includes information on the reception strength of the reference signal received at the current position. The transformation matrix calculation unit receives the current position information calculated by the final position determination unit (S704). The current position can be calculated as described with reference to Fig.

Thereafter, the transformation matrix calculation unit calculates the reference signal reference reception intensity at the current position using the wireless map information and the current position information (S706). For example, using the current position information and the wireless map information, the reference signal reference reception strength at the current position can be calculated. That is, the conversion matrix calculator can estimate and calculate the reference signal reference reception strength at the current position, not the reference point, using the reference signal reference reception intensity information at the reference point in the wireless map. Specifically, the reference signal reference reception strength at the current position can be calculated by Equation (9).

는 l 지점에서의 산출된 기준신호 기준 수신강도를 의미한다. 수학식 9에서

는 s번째 기준신호 송신장치를 나타내고,

는 무선 맵 내에서 저장된 s번째 기준지점에서의 기준신호 기준 수신강도를 나타낸다. 또한

는 각 s번째 기준지점의 가중치를 나태나고, 가중치의 총합은 1이다.
In Equation (9)

Denotes the reference signal reference reception strength calculated at point l. In Equation (9)

Denotes an s-th reference signal transmitting apparatus,

Represents the reference signal reference reception strength at the s-th reference point stored in the wireless map. Also

Is the weight of each s-th reference point, and the sum of the weights is 1.

)와 시점 t에서의 실제 수신된 기준신호 수신강도(

)를 인자로 하여 수학식 10을 통해서 예비 변환행렬을 산출한다.The transform matrix calculator calculates a preliminary transform matrix using the reference signal reference intensities at the current position and the actually received reference signal intensities calculated through Equation (9) (S708). For example, the reference signal reference reception intensity at the estimated current position (

) And the actually received reference signal reception intensity at time t (

) As a factor, the preliminary transformation matrix is calculated by Equation (10).

는 시점 t에서의 예비 변환행렬 원소 a를 의미한다. 수학식 10을 통해서 각 원소의 값이 산출되면, 예비 변환행렬

을 산출할 수 있다. 예비 변환행렬은 현재위치에서의 기준신호 기준 수신강도와 실제 수신된 기준신호 수신강도의 오차에 대한 정보를 포함할 수 있다.

Denotes the pre-transformation matrix element a at time t. When the value of each element is calculated through Equation (10), the pre-conversion matrix

Can be calculated. The pre-conversion matrix may include information on the error of the reference signal reception intensity at the current position and the actually received reference signal reception intensity.

Meanwhile, the transformation matrix calculation unit may receive the transformation matrix information used in the position estimation unit and the movement information used in the position prediction unit (S710). For example, the transformation matrix used in the position estimation unit may refer to the next transformation matrix information calculated at the previous position. In addition, the terminal can receive the movement information generated as the terminal moves from the previous position to the predicted position.

)과 추정 위치 산출단계에서 사용된 이전 위치에서의 변환 행렬(

)은 관성 측정장치에서 측정된 이동정보에 따라 수학식 11과 같이 다음 시점에서의 차기 변환 행렬을 예측할 수 있다.Thereafter, the transformation matrix calculator may calculate the next transformation matrix information based on the preliminary transformation matrix information, the transformation matrix information, and the movement information (S712). For example, the transform matrix calculator may calculate the pre-transform matrix (

) And the transformation matrix at the previous position used in the estimated position calculation step (

Can predict the next transformation matrix at the next time point as shown in Equation (11) according to the movement information measured by the inertial measurement apparatus.

는 이동 변화량에 따른 변수를 나타낸다. 수학식 11에서 예측한 차기 변환행렬(

)은 다음 시점에서 사용될 변환 행렬을 나타낸다.In Equation (11)

Represents a variable according to the amount of movement change. The next conversion matrix predicted in Equation (11)

) Represents the transformation matrix to be used at the next time point.

Through the above-described operation, the transformation matrix calculation unit calculates the next transformation matrix to be used at the next time point.

However, when the terminal is in the initial position, the terminal can not receive the movement information because there is no previous position information. Therefore, in this case, the next transformation matrix calculated by the transformation matrix calculation unit is calculated based on only the reference signal reception intensity at the initial position and the reference signal reference reception intensity at the initial position. That is, the preliminary transformation matrix calculated using Equation (10) can be the next transformation matrix. However, since the information on the previous position and the movement information using the previous position are known after the initial position, the next transformation matrix according to Equation (11) is calculated.

8 is a view for explaining calculation of the next conversion matrix information according to another embodiment of the present invention.

The above-described next conversion matrix calculation method will be described again conceptually with reference to Fig.

Referring to FIG. 8, a terminal according to another embodiment of the present invention can calculate a predicted position 801 using movement information and previous position 890 information in a position predictor. Also, the terminal can calculate the estimated position 805 using the fingerprinting method in the position estimating unit. That is, the terminal calculates the estimated position 805 using the reference signal reception strength 815 information. Then, the terminal can calculate the current position 800 by the operation of the last positioning unit described above.

When the current position 800 is determined, the terminal calculates a reference signal reference reception strength 810 to be received at the current position 800 using Equation (9). When the reference signal reference reception strength 810 at the current location 800 is calculated, the terminal calculates the pre-conversion matrix using the actually received reference signal reception intensity 815 information. The preliminary transformation matrix can be calculated using Equation (10).

When the terminal generates the preliminary transformation matrix, it can calculate the next transformation matrix using the preliminary transformation matrix, the movement information, and the transformation matrix used for calculating the estimated position (805). The next transformation matrix calculation can be calculated using Equation (11).

Through the above operation, the terminal of the present invention can continuously update the transformation matrix to be used at the next location, and it is possible to calculate the estimated position using the accurate transformation matrix and consequently to accurately determine the current position.

9 is a diagram illustrating an operation of calculating a next transformation matrix at an initial position according to another embodiment of the present invention.

In calculating a next transformation matrix according to another embodiment of the present invention, the operation may be differently applied in an initial position where the first terminal is located. For example, when the terminal exists in the initial position, since there is no information on the previous position and there is no movement information, the above-described next transformation matrix calculation method and its operation may operate in some different ways.

Referring to FIG. 9, in the initial position, the terminal can receive the initial position information (S902). The initial position information may be received according to the user input signal. Or by a position sensor such as GPS. For example, when a user inputs position information of a current terminal through a map application or the like, the position information may be received as initial position information.

The terminal receives the reference signal according to the fingerprinting method described above (S904). The reference signal is a signal transmitted from each of the plurality of reference signal transmitting apparatuses, and the terminal measures the receiving strength of the reference signal.

Also, the terminal can calculate the reference signal reference reception strength at the initial position using the wireless map information (S906). The terminal knows the initial position information and can obtain the reference signal reference reception strength information of each reference point in the wireless map. Therefore, the reference signal reference reception strength to be received at the initial position can be calculated. The reference signal reference reception strength can be calculated using Equation (9).

The terminal calculates the next change matrix information using the reference signal reference reception strength at the calculated initial position and the actually received reference signal reception strength at step S908. For example, the next transformation matrix calculated at the initial position may be used as a transformation matrix in estimating the position after the UE moves to the initial change matrix. The next transformation matrix calculated at the initial position can be calculated using Equation (10).

As described above, when the terminal knows the initial position information at the initial point, the terminal calculates the next transformation matrix, and then, according to the movement of the terminal, performs the operation of the present invention as described above and uses the PDR and the current position using the fingerprinting method . Then, the terminal that has calculated the current position calculates the next transformation matrix considering the movement information using Equation (11) as it receives the movement information.

Hereinafter, a position calculation method capable of performing all the operations of the terminal for estimating the position of the present invention described with reference to Figs. 1 to 9 will be described.

10 is a diagram illustrating a position calculating method according to another embodiment of the present invention.

According to another aspect of the present invention, there is provided a method for calculating a position of a terminal, the method comprising: a position estimation step of calculating a predicted position based on previous positional information and movement information received from an inertial measurement device; Based on the reception intensity of the reference signal, the radio map information in which the reference reception intensities of the reference signals received at the plurality of reference points are stored for each of a plurality of reference points, and the conversion matrix information for correcting the reception intensities of the reference signals A final position determining step of calculating a current position of the terminal based on the predicted position and the estimated position, and a transform matrix calculating step of calculating the next transform matrix information used in the next position estimation of the terminal .

Referring to FIG. 10, the position calculating method includes a position estimating step of calculating a predicted position based on previous position information and movement information received from the inertial measurement apparatus (S1002). For example, the position estimation step uses the previous position of the terminal as a reference point, and calculates the predicted position according to the movement direction and the movement distance using the movement information received from the inertial measurement device. That is, the predicted position of the terminal can be calculated using the above-described PDR positioning algorithm.

In addition, the position calculating method may include calculating a reception intensity of the reference signal received from each of the one or more reference signal transmitting apparatuses, a radio map storing a reference reception intensity of each of the reference signals received at the plurality of reference points, And a position estimation step of calculating an estimated position based on the information and the conversion matrix information for correcting the reception intensity of the reference signal (S1004). For example, the position estimation step generates a reference signal conversion reception intensity using the reference signal reception intensity and the conversion matrix information received by the terminal, and outputs the estimated position according to the fingerprinting positioning method using the generated reference signal conversion reception intensity . The transform matrix information is generated at the previous position and is used as a correction factor for correcting the reference signal reception intensity value that may vary depending on the surrounding environment or terminal characteristics.

The position calculating method may include a final positioning step of calculating a current position of the terminal based on the predicted position and the estimated position (S1006). For example, the final positioning step may finally calculate the current position using the calculated predicted position and estimated position, respectively. For example, the current position can be calculated by fusing the predicted position and the current position using the Kalman filter algorithm. Specifically, the Kalman gain can be generated using Equations 5 to 8 described above, and the current position can be calculated using the generated Kalman gain, predicted position information, and estimated position information.

The position calculation method may include a transformation matrix calculation step of calculating a next transformation matrix information to be used for the next position estimation of the terminal. For example, the UE calculates a preliminary conversion matrix using the reference signal reception strength and the reference signal reception strength to be received at the current position, and performs a next conversion process using the conversion matrix used for calculating the movement information and the estimated position And calculates a matrix. That is, the terminal can use Equation (11). The next transformation matrix is used as the transformation matrix at the next point.

In addition, the position calculating method of the present invention can perform all the operations of the terminal described with reference to FIGS. 1 to 9. For example, in calculating the next transformation matrix at the initial point, the position calculation method can perform the operation described with reference to FIG. 9 without using the movement information.

That is, the location estimation method of the present invention will be briefly described with reference to an initial point as an initial point. When the terminal receives information on an initial point, the terminal calculates a reference signal reference reception intensity to be received at an initial point on the wireless map . The terminal generates a pre-conversion matrix using the reference signal reference reception strength to be received at the calculated initial point and the actually received reference signal reception strength. The pre-transformation matrix at the initial point is used as the transformation matrix at the next point.

Thereafter, when the mobile station moves, a predicted position is calculated using the initial point information and the movement information to estimate the moved position, and using the received signal strength received at the moved position and the transform matrix generated at the initial point Calculate the reference signal conversion reception strength. The terminal calculates the estimated position according to the fingerprinting method using the calculated reference signal conversion reception intensity and wireless map information.

The terminal fuses the predicted position and the estimated position using a Kalman filter algorithm to calculate the current position. The MS calculates the preliminary conversion matrix using the reference signal reception strength and the reference signal reception strength to be received at the current position, and calculates a next conversion matrix using the conversion matrix used for calculating the movement information and the estimated position do. The next transformation matrix is used as the transformation matrix at the next point.

Thereafter, when the terminal moves, the predicted position and the estimated position are calculated, and the operation of using the current position is repeatedly performed to calculate the position.

As described above, according to the present invention, the final position of the terminal is determined by using the position estimation value of the fingerprinting method using the movement information of the terminal using the inertial measurement device and the reference signal reception strength. In addition, the present invention provides an effect of further improving the accuracy of position estimation of the fingerprinting scheme by using the correction conversion matrix value that takes into consideration that the reference signal reception intensity is changed according to the surrounding environment. Further, the present invention provides the effect of continuously calculating the transformation matrix at the next time point to provide a more accurate next transformation matrix.

Although the location calculation method according to the embodiment of the present invention has been described above as being performed by the procedure as shown in FIG. 10, it is only for convenience of explanation, and it should be noted that within the scope of the present invention, Accordingly, the execution procedure of each step may be changed, or two or more steps may be integrated, or one step may be performed in two or more steps.

In addition, the terminal may include a general PC such as a general desktop or a notebook computer, and may include a mobile terminal such as a smart phone, a tablet PC, a PDA (Personal Digital Assistants), and a mobile communication terminal. It should be broadly interpreted as any electronic device capable of wireless communication.

The location calculation method according to the embodiment of the present invention described above can be executed by an application installed in the terminal (which may be included in a platform that is basically installed in the terminal or included in an operating system or compatible with the terminal) , And may also be executed by an application (that is, a program) that is compatible with the operating system of the terminal and directly installed on the terminal through the application providing server such as an application store server, an application or a web server related to the service. Here, the operating system of the terminal may be an operating system such as a window, a Macintosh, or Linux installed in a general PC such as a desktop, iOS installed in a mobile terminal such as a smart phone or a tablet PC, (Android), Windows Mobile and other mobile-specific operating systems.

In this sense, the position calculation method according to the embodiment of the present invention described above is implemented as an application (i.e., a program) that is basically installed in a terminal or directly installed by a user and is recorded in a computer- .

A program for executing a method for calculating a position of a terminal according to an embodiment of the present invention includes a position prediction function for calculating a predicted position based on previous positional information and movement information received from the inertial measurement device, A radio map information storing a reference reception strength of each of the plurality of reference points received at the plurality of reference points and a conversion matrix information for correcting the reception intensity of the reference signal, A final position determination function for calculating the current position of the terminal based on the predicted position and the estimated position, and a conversion matrix calculation for calculating the next transformation matrix information used for the next position estimation of the terminal Function can be executed.

Such a program may be recorded on a recording medium that can be read by a computer and executed by a computer so that the above-described functions can be executed.

As described above, in order for the computer to read the program recorded on the recording medium and to execute the position calculating method implemented by the program, the program may be stored in a computer such as a C, C ++, JAVA, And may include a code encoded in a language.

The code may include a function code related to a function or the like that defines the functions described above and may include an execution procedure related control code necessary for the processor of the computer to execute the functions described above according to a predetermined procedure.

In addition, such code may further include memory reference related code as to what additional information or media needed to cause the processor of the computer to execute the aforementioned functions should be referenced at any location (address) of the internal or external memory of the computer .

In addition, when a processor of a computer needs to communicate with any other computer or server, etc., to perform the above-described functions, the code may be stored in a computer's communication module (e.g., a wired and / ) May be used to further include communication related codes such as how to communicate with any other computer or server in the remote, and what information or media should be transmitted or received during communication.

The functional program for implementing the present invention and the related code and code segment may be implemented by programmers in the technical field of the present invention in consideration of the system environment of the computer that reads the recording medium and executes the program, Or may be easily modified or modified by the user.

Also, the computer-readable recording medium on which the above-described program is recorded may be distributed to a computer system connected via a network so that computer-readable codes can be stored and executed in a distributed manner. In this case, one or more of the plurality of distributed computers may execute some of the functions presented above and send the results of the execution to one or more of the other distributed computers, The computer may also perform some of the functions described above and provide the results to other distributed computers as well.

As described above, the computer-readable recording medium on which the program for executing the position calculating method according to the embodiment of the present invention is recorded may be a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, Optical media storage devices.

Further, a computer-readable recording medium storing an application, which is a program for executing a position calculating method according to an embodiment of the present invention, includes an application store server, an application or a web server related to the service (E.g., a hard disk, etc.) included in an application provider server including an application server, etc., or may be an application providing server itself, another computer storing the program, or a storage medium thereof.

A computer capable of reading a recording medium on which an application, which is a program for executing a position calculating method according to an embodiment of the present invention, can be read is not limited to a general PC such as a general desktop or a notebook computer but also a smart phone, Digital assistants, and mobile communication terminals. In addition, the present invention should be interpreted as all devices capable of computing.

If a computer capable of reading a recording medium on which an application, which is a program for executing the position calculating method according to an embodiment of the present invention, is read is a mobile terminal such as a smart phone, a tablet PC, a PDA (Personal Digital Assistants) , The mobile terminal can download and install the application from an application providing server including an application store server and a web server. In some cases, after downloading from the application providing server to a general PC, Or may be installed in the terminal.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them. In addition, although all of the components may be implemented as one independent hardware, some or all of the components may be selectively combined to perform a part or all of the functions in one or a plurality of hardware. As shown in FIG. The codes and code segments constituting the computer program may be easily deduced by those skilled in the art. Such a computer program can be stored in a computer-readable storage medium, readable and executed by a computer, thereby realizing an embodiment of the present invention. As a storage medium of the computer program, a magnetic recording medium, an optical recording medium, or the like can be included.

It is also to be understood that the terms such as " comprises, "" comprising," or "having ", as used herein, mean that a component can be implanted unless specifically stated to the contrary. But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (12)

In a terminal for calculating a position,
A position predicting unit for calculating a predicted position based on previous positional information and movement information received from the inertial measurement device;
A reception intensity of a reference signal received from each of the one or more reference signal transmission apparatuses, a radio map information storing a reference reception intensity of each of the reference signals received at the plurality of reference points for each of the plurality of reference points, A position estimator for calculating an estimated position based on the transformation matrix information for correcting the reception intensity of the signal;
A final position determination unit for calculating a current position of the terminal based on the predicted position and the estimated position; And
And a transform matrix calculation unit for calculating a next transform matrix information to be used for the next position estimation of the terminal,
The next conversion matrix information includes:
And is used as the transformation matrix information for calculating the estimated position at the next position. The method according to claim 1,
The position predicting unit,
And calculates the predicted position using at least one of moving speed information, moving distance information, and moving direction information included in the moving information based on the previous position information. 3. The method of claim 2,
The position predicting unit,
Wherein the predicted position is calculated using a pedestrian dead reckoning algorithm. The method according to claim 1,
The position estimating unit may calculate,
And the estimated position is calculated by correcting the reception intensity of the reference signal to the reference signal conversion reception intensity using the conversion matrix and comparing the reception intensity of the reference signal conversion with the wireless map information. 5. The method of claim 4,
The position estimating unit may calculate,
Wherein the estimated position is calculated through a fingerprinting positioning algorithm based on the reference signal conversion reception intensity and the wireless map information. delete The method according to claim 1,
Wherein the transformation matrix calculator comprises:
And calculates the next conversion matrix information based on at least one of the movement information, the conversion matrix information, the received reference signal reception strength, and the reference signal reference reception strength estimated using the wireless map information at the current position . 8. The method of claim 7,
Wherein the transformation matrix calculator comprises:
Wherein the preliminary conversion matrix information is calculated based on the received reference signal reception intensity and the reference signal reception intensity estimated using the wireless map information at the current location, And calculates the next conversion matrix information based on the information. The method according to claim 1,
Wherein the final position determining unit comprises:
And calculates a current position of the terminal using the predicted position, the estimated position, and a Kalman filter algorithm. 10. The method of claim 9,
Wherein the final position determining unit comprises:
Calculates a Kalman gain using a covariance value of the predicted position and a covariance value with respect to the estimated position error,
And calculates the current position of the terminal using the predicted position, the estimated position, and the Kalman gain. A method for calculating a position of a terminal,
A position predicting step of calculating a predicted position based on the previous positional information and the movement information received from the inertial measurement device;
A reception intensity of a reference signal received from each of the one or more reference signal transmission apparatuses, a radio map information storing a reference reception intensity of each of the reference signals received at the plurality of reference points for each of the plurality of reference points, A position estimation step of calculating an estimated position based on conversion matrix information for correcting a reception intensity of a signal;
A final positioning step of calculating a current position of the terminal based on the predicted position and the estimated position; And
And a transform matrix calculation step of calculating a next transform matrix information to be used for the next position estimation of the terminal,
The next conversion matrix information includes:
And the transform matrix information is used as the transform matrix information for calculating the estimated position at the next position. A recording medium on which a program for executing a method for calculating a position of a terminal is recorded,
A position prediction function for calculating a predicted position based on previous positional information and movement information received from the inertial measurement device;
A reception intensity of a reference signal received from each of the one or more reference signal transmission apparatuses, a radio map information storing a reference reception intensity of each of the reference signals received at the plurality of reference points for each of the plurality of reference points, A position estimation function for calculating an estimated position based on conversion matrix information for correcting a reception intensity of a signal;
A final positioning function for calculating a current position of the terminal based on the predicted position and the estimated position; And
A transformation matrix calculation function for calculating a next transformation matrix information to be used for next position estimation of the terminal,
The next conversion matrix information includes:
And the transformation matrix information for calculating the estimated position at the next position is used as the transformation matrix information.

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