KR20180121020A - Apparatus and method for estimating position of terminal - Google Patents

Abstract

The present invention discloses a method and a device for estimating a position of a terminal in a communication network, which can reduce a computation amount required in a process of estimating a position of a terminal. The disclosed method for estimating a position of a terminal comprises the following steps of: obtaining time stamp values representing a time receiving a signal from the terminal by base stations; determining a candidate region for the position of the terminal based on positions of the base stations and the time stamp values; and determining a position coordinate of the terminal based on the time stamp values within the candidate region.

Description

[0001] APPARATUS AND METHOD FOR ESTIMATING POSITION OF TERMINAL [0002]

The present invention relates to an apparatus and method for estimating a position of a terminal, and an apparatus and method for estimating a position of a terminal based on a Time Difference of Arrival (TDoA) scheme.

Of the services that the terminal receives in the mobile communication network, there is a service based on the location of the terminal. In the case of the terminal location based service, accurate location information of the terminal is required in order to properly cope with various events occurring in the mobile communication network.

The conventional method of estimating the outdoor position is based on the Global Navigation Satellite System (GNSS) / Global Positioning System (GPS). However, the GNSS / GPS technology used in existing position estimation systems is not suitable for communication nodes with limited processing power and power due to high computational load and high power consumption. In recent years, the launch of Low Power Wide Area (LPWA) communication technologies such as LoRa and LTE-M has led to the need for location estimation technology that can be used in mountainous areas that have been a limitation of existing GNSS.

One technique for estimating the position of a terminal is a technique using RSSI (Received Signal Strength Indicator) information. According to the RSSI-based technique, when a terminal sends a packet for location estimation, each base station can calculate its signal strength (RSSI) for the packet and calculate the distance between the terminal and the base stations from the signal strength values . Then, the base station can calculate the position of the terminal by the triangulation method. However, since the RSSI is calculated based on the log value, there is a problem that the error of the estimated position increases.

The Time of Arrival (ToA) technique is divided into unidirectional and bidirectional. The unidirectional ToA technique can calculate the distance between the base stations and the terminal using the difference between the transmission timestamp and the reception timestamp value of the packet when the terminal transmits the packet. However, the unidirectional ToA technique is required as precondition that the time synchronization between the base stations and the terminal is precisely performed.

The bidirectional ToA technique is advantageous in that it can be applied without time synchronization between the terminal and the base station. When a terminal transmits a packet, the base stations receiving the packet can transmit the packet again to the terminal. The MS receives the retransmitted packet and calculates the distance between the BS and the MS based on the difference between the time of the first transmission and the time of receiving the retransmitted packet. However, there is a problem that when calculating the internal signal processing time of the base station, the error must be nano seconds or less in order to apply the technique.

The present invention proposes a method and apparatus for estimating the position of a UE based on the TDoA scheme. Also, a method and apparatus for reducing the amount of computation required in the process of estimating the position of the terminal are proposed.

According to another aspect of the present invention, there is provided a method for estimating a location of a terminal in a communication network,

Obtaining timestamp values indicating a time when a plurality of base stations received a signal from the terminal;

Determining a candidate region for a location of the terminal based on the location of the base stations and the timestamp values; And

And determining the position coordinates of the terminal based on the time stamp values in the candidate region.

Wherein the step of determining the candidate region comprises:

Select a first pair of base stations from among the base stations and determine a first candidate region based on time stamp values received from the first pair of base stations.

The boundary of the first candidate region may be determined by a vertical bisector between the first pair of base stations.

Wherein the step of determining the candidate region comprises:

Selecting a second pair of base stations different from the first pair among the base stations and determining a second candidate region within the first candidate region based on timestamp values received from the second pair of base stations have.

The boundary of the second candidate region may be determined by a vertical bisector between the second pair of base stations.

Wherein the step of determining the candidate region comprises:

k th candidate base stations based on time stamp values received from the kth pair of base stations,

k th candidate region and the (k + 1) th candidate region based on the time stamp values received from the (k + 1) th base stations.

보다 작거나 같은 자연수, n은 기지국들의 개수)(k is

Less than or equal to a natural number, and n is the number of base stations)

Wherein the step of determining the location coordinates of the terminal comprises:

Based on the timestamp values, at least one of a plurality of candidate coordinates in the candidate region may be determined.

Wherein the step of determining the location coordinates of the terminal comprises:

The location coordinates of the terminal can be determined by comparing the difference between the time stamp values corresponding to each of the plurality of candidate coordinates and the time stamp value received from the base stations.

The difference between the timestamp values corresponding to each of the plurality of candidate coordinates may be determined by the distance between each of the candidate coordinates and the base stations.

Wherein the step of determining the location coordinates of the terminal comprises:

One of the plurality of candidate coordinates may be determined as the position coordinates of the terminal.

Wherein the step of determining the location coordinates of the terminal comprises:

The mobile terminal can select two or more candidate coordinates among the plurality of candidate coordinates and determine the coordinates between the two or more candidate coordinates as the position coordinates of the terminal.

An apparatus for estimating a terminal location in a communication network, according to an embodiment of the present invention,

A processor; And

Wherein at least one instruction executed through the processor includes a memory,

Wherein the at least one instruction comprises:

The method includes obtaining a time stamp value indicating a time when a plurality of base stations received a signal from the terminal, determining a candidate region for the position of the terminal based on the positions of the base stations and the time stamp values, Based on the time stamp values, to determine the position coordinates of the terminal.

Wherein the at least one instruction comprises:

Selecting a first pair of base stations from among the base stations and determining a first candidate region based on time stamp values received from the first pair of base stations.

The boundary of the first candidate region may be determined by a vertical bisector between the first pair of base stations.

Wherein the at least one instruction comprises:

Selecting a second pair of base stations different from the first pair among the base stations and determining a second candidate region within the first candidate region based on time stamp values received from the second pair of base stations .

The boundary of the second candidate region may be determined by a vertical bisector between the second pair of base stations.

Wherein the at least one instruction comprises:

k th candidate base stations based on time stamp values received from the kth pair of base stations,

k th candidate region and the (k + 1) th candidate region based on the time stamp values received from the (k + 1) th base stations.

보다 작거나 같은 자연수, n은 기지국들의 개수)(k is

Less than or equal to a natural number, and n is the number of base stations)

Wherein the at least one instruction comprises:

And to determine at least one of a plurality of candidate coordinates in the candidate region based on the timestamp values.

Wherein the at least one instruction comprises:

And comparing the difference between the time stamp values corresponding to each of the plurality of candidate coordinates and the time stamp value received from the base stations to determine the position coordinates of the terminal.

The difference between the timestamp values corresponding to each of the plurality of candidate coordinates may be determined by the distance between each of the candidate coordinates and the base stations.

According to the present invention, according to the above-described embodiments, the position of the terminal can be estimated by the TDoA scheme. Further, by setting the candidate region and determining the position coordinates of the terminal within the candidate region, it is possible to reduce the calculation amount and time required for estimating the position of the terminal.

1 is a block diagram illustrating a communication node performing a method of operating a communication node in a communication network according to an embodiment of the present invention.
2 is a flowchart illustrating a method of estimating a position of a terminal according to an exemplary embodiment of the present invention.
3 is a conceptual diagram illustrating that base stations receive a signal from a terminal.
4 is a conceptual diagram illustrating a process of the terminal position estimation apparatus determining a first candidate region.
5 is a conceptual diagram illustrating a process of determining a second candidate region by the terminal location estimation apparatus.
6 is a conceptual diagram illustrating a process of the terminal position estimation apparatus determining a third candidate region.
7 is a conceptual diagram illustrating a process of the terminal position estimation apparatus determining a fourth candidate region.
FIG. 8 is a flowchart illustrating a candidate region determination process described with reference to FIGS.
9 is a conceptual diagram illustrating an example in which the terminal position estimation apparatus selects candidate coordinates within a candidate region.
FIG. 10 is a flowchart illustrating a process of performing step S130 of FIG.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the present invention, the same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

Throughout the specification, the network can be, for example, a wireless Internet such as WiFi (wireless fidelity), a wireless broadband internet (WiBro) or a portable internet such as world interoperability for microwave access (WiMax) A 3G mobile communication network such as a Wideband Code Division Multiple Access (WCDMA) or CDMA2000, a high speed downlink packet access (HSDPA), or a high speed uplink packet access (HSUPA) A 3.5G mobile communication network, a 4G mobile communication network such as an LTE (Long Term Evolution) network or an LTE-Advanced network, a 5G mobile communication network, and a C-RAN (Cloud Radio Access Network).

Throughout the specification, a terminal is referred to as a mobile station, a mobile terminal, a subscriber station, a portable subscriber station, a user equipment, an access terminal, A terminal, a mobile station, a mobile station, a subscriber station, a mobile subscriber station, a user equipment, an access terminal, and the like.

Here, the terminal may include a sensor that is attached to the object and can communicate with the object. Sensors attached to objects can be used to implement Internet Of Things (IOT). The terminal may be a desktop computer, a laptop computer, a tablet PC, a wireless phone, a mobile phone, a smart phone, a smart watch, ), Smart glass, an e-book reader, a portable multimedia player (PMP), a portable game machine, a navigation device, a digital camera, a digital multimedia broadcasting (DMB) player, a digital voice recorder an audio recorder, a digital audio player, a digital picture recorder, a digital picture player, a digital video recorder, a digital video player, Lt; / RTI >

Throughout the specification, a base station is referred to as an access point, a radio access station, a node B, an evolved node B, a base transceiver station, an MMR mobile multihop relay) -BS, and may include all or some of the functions of a base station, an access point, a radio access station, a Node B, an eNodeB, a base transceiver station, and a MMR-BS.

Hereinafter, a method of operating a communication node in a communication network according to an embodiment of the present invention and a communication node performing the same will be described.

1 is a block diagram illustrating a communication node performing a method of operating a communication node in a communication network according to an embodiment of the present invention.

Referring to FIG. 1, a communication node 100 may include at least one processor 110, a memory 120, and a network interface device 130 for communicating with a network. The communication node 100 may further include an input interface device 140, an output interface device 150, a storage device 160, and the like. Each component included in the communication node 100 may be connected by a bus 170 and communicate with each other.

The processor 110 may execute a program command stored in the memory 120 and / or the storage device 160. The processor 110 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the methods of the present invention are performed. The memory 120 and the storage device 160 may be composed of a volatile storage medium and / or a non-volatile storage medium. For example, the memory 120 may be comprised of read only memory (ROM) and / or random access memory (RAM). Here, a program instruction executed through the processor 310 may include a plurality of steps for performing a method of operating a communication node in the communication network proposed by the present invention.

2 is a flowchart illustrating a method of estimating a position of a terminal according to an exemplary embodiment of the present invention.

The method shown in Fig. 2 can be performed by the terminal position estimation apparatus. The terminal location estimation apparatus may be any one of base stations constituting the communication network. In this case, the terminal position estimation apparatus can record the time at which the signal was received from the terminal UE. And, from at least some of the other base stations, at least some base stations can obtain time stamp values recording the time at which the signal was received from the terminal (UE). As another example, the terminal location estimation apparatus may be physically separated from the base station.

In step S110, the terminal location estimation apparatus may obtain time stamp values indicating the time when the base stations received the signal from the terminal.

3 is a conceptual diagram illustrating that base stations receive a signal from a terminal.

Referring to FIG. 3, the UE may transmit a signal for estimating the position of the UE. The base stations BS1, BS2, BS3, and BS4 may receive signals transmitted by the UE. The base stations BS1, BS2, BS3, and BS4 can record the time at which the signal is received from the terminal UE. The times of the base stations (BS1, BS2, BS3, BS4) may be synchronized with each other. The time stamp means information on the time at which the base stations BS1, BS2, BS3, and BS4 received the signal of the terminal UE. The time stamp value may vary depending on the distance between the base stations (BS1, BS2, BS3, BS4) and the terminal (UE).

For example, since the fourth base station BS4 is closer to the terminal UE than the first base station BS1, the time stamp value of the fourth base station BS4 may be smaller than the time stamp value of the first base station BS1 have. The terminal location estimation apparatus can estimate the distance between the base stations BS1, BS2, BS3, BS4 and the terminal UE from the time stamp values of the base stations BS1, BS2, BS3, BS4. The terminal location estimation apparatus can estimate the location coordinates of the terminal from the difference of the time stamp values of the base stations BS1, BS2, BS3, BS4. A method of estimating the position of the UE using the time difference between the BSs BS1, BS2, BS3, and BS4 receiving the signal of the UE is thus referred to as a Time Difference of Arrival (TDoA) scheme.

 In the TDoA scheme, time synchronization between the UE and the BSs BS1, BS2, BS3, and BS4 is not required. However, a large amount of computation may be consumed in estimating the position of the UE from the difference of the time stamp values of the base stations BS1, BS2, BS3, and BS4. Therefore, if the number of terminals requesting the position estimation increases, sufficient quality of service may not be guaranteed.

Referring back to FIG. 2, in step S120, the terminal position estimation apparatus calculates a position based on the positions of the base stations BS1, BS2, BS3 and BS4 and the time stamp values obtained from the base stations BS1, BS2, BS3 and BS4 , It is possible to determine a candidate region for the location of the terminal UE. Hereinafter, a process of determining a candidate region will be described with reference to FIGS. 4 to 7. FIG.

FIG. 4 is a conceptual diagram illustrating a process in which the terminal location estimation apparatus determines a first candidate region S1.

Referring to FIG. 4, the terminal location estimation apparatus may select a first pair of base stations among the base stations BS1, BS2, BS3, and BS4. For example, the terminal location estimation apparatus may select the first base station BS1 and the second base station BS2 as the first pair of base stations.

The terminal location estimation apparatus can compare the time stamp value obtained from the first base station BS1 with the time stamp value obtained from the second base station BS2. 4, since the first base station BS1 is farther from the terminal UE than the second base station BS2, the time stamp value acquired from the first base station BS1 is longer than the time acquired from the second base station BS2 May be greater than the stamp value.

The terminal location estimation apparatus can determine the second base station BS2 side region closer to the terminal UE among the first and second base stations BS1 and BS2 as the first candidate region S1. The terminal location estimation apparatus can calculate the vertical bisector between the first base station BS1 and the second base station BS2 based on the positions of the first base station BS1 and the second base station BS2. The terminal location estimation apparatus can determine the vertical bisector L12 between the first base station BS1 and the second base station BS2 as the boundary of the first candidate region S1.

5 is a conceptual diagram illustrating a process of the terminal location estimation apparatus determining a second candidate region S2.

Referring to FIG. 5, the terminal location estimation apparatus may select a second pair of base stations among the base stations BS1, BS2, BS3 and BS4. The second pair of base stations may be different from the first pair of base stations. The fact that the base stations included in the second pair and the first pair of base stations are different from each other means that not all of the base stations included in the second pair coincide with all of the base stations included in the first pair. Thus, any of the base stations included in the second pair may be the same as either of the first pair of base stations. Alternatively, the base stations included in the second pair may not all be included in the first pair.

For example, the terminal location estimation apparatus may select the second base station BS2 and the fourth base station BS4 as the second pair of base stations.

The terminal location estimation apparatus can compare the time stamp value obtained from the second base station BS2 with the time stamp value obtained from the fourth base station BS4. 5, since the second base station BS2 is farther from the terminal UE than the fourth base station BS4, the time stamp value acquired from the second base station BS2 is longer than the time acquired from the fourth base station BS4 May be greater than the stamp value.

The terminal location estimation apparatus can determine the second candidate region S2 within the first candidate region S1. Therefore, the second candidate region S2 may be smaller than or equal to the first candidate region S1. The terminal location estimation apparatus can determine the fourth base station BS4 side region closer to the terminal UE among the second and fourth base stations BS2 and BS4 as the second candidate region S2. The terminal position estimation apparatus can calculate the vertical bisector between the second base station BS2 and the fourth base station BS4 based on the positions of the second base station BS2 and the fourth base station BS4. The terminal location estimation apparatus can determine the vertical bisector L24 between the second base station BS2 and the fourth base station BS4 as the boundary of the second candidate region S2.

6 is a conceptual diagram illustrating a process of the terminal position estimation apparatus determining a third candidate region S3.

Referring to FIG. 6, the terminal location estimation apparatus can select a third pair of base stations among the base stations BS1, BS2, BS3, and BS4. The third pair of base stations may be different from the first pair of base stations and the second pair of base stations.

For example, the terminal location estimation apparatus may select the second base station BS2 and the third base station BS3 as the third pair of base stations.

The terminal location estimation apparatus can compare the time stamp value obtained from the second base station BS2 with the time stamp value obtained from the third base station BS3. 6, since the second base station BS2 is farther from the terminal UE than the third base station BS3, the time stamp value obtained from the second base station BS2 is longer than the time acquired from the third base station BS3 May be greater than the stamp value.

The terminal location estimation apparatus can determine the third candidate region S3 within the second candidate region S2. Therefore, the third candidate region S3 may be smaller than or equal to the second candidate region S2. The terminal location estimation apparatus can determine the third base station BS3 side region closer to the terminal UE among the second and third base stations BS2 and BS3 as the third candidate region S3. The terminal location estimation apparatus can calculate the vertical bisector between the second base station BS2 and the third base station BS3 based on the positions of the second base station BS2 and the third base station BS3. The terminal location estimation apparatus can determine the vertical bisector L23 between the second base station BS2 and the third base station BS3 as the boundary of the third candidate region S3.

7 is a conceptual diagram illustrating a process of the terminal location estimation apparatus determining a fourth candidate region S4.

Referring to FIG. 7, the terminal location estimation apparatus may select a fourth pair of base stations among the base stations BS1, BS2, BS3, and BS4. The fourth pair of base stations may be different from the first pair of base stations, the second pair of base stations and the third pair of base stations.

For example, the terminal location estimation apparatus may select the first base station BS1 and the fourth base station BS4 as the fourth pair of base stations.

The terminal position estimation apparatus can determine the fourth region S4 in the third region S3. Therefore, the fourth candidate region S4 may be smaller than or equal to the third candidate region S3.

The terminal position estimation apparatus can calculate the vertical bisector L14 between the first base station BS1 and the fourth base station BS4. The terminal position estimation apparatus can determine the fourth candidate region S4 as the reference nearer to the fourth base station BS4 on the basis of the vertical bisector L14. However, since the vertical bisector L14 does not cross the existing third candidate region S3, the fourth candidate region S4 may be the same as the third candidate region S3.

Since there are a total of four base stations BS1, BS2, BS3 and BS4 in FIGS. 3 to 7, a total of six base stations can be selected. However, the vertical bisector between the third base station BS3 and the fourth base station BS4 may coincide with the vertical bisector between the first base station BS1 and the second base station BS2. In addition, the vertical bisector between the first base station BS1 and the third base station BS3 may coincide with the vertical bisector between the second base station BS2 and the fourth base station BS4.

As mentioned above, the process of determining the candidate region can be omitted when the vertical bisector which is the same as the vertically bisected line considered in the prior art is calculated. Therefore, the fourth candidate region S4 shown in Fig. 7 or the third candidate region S3 shown in Fig. 6 can be determined as the final candidate region.

FIG. 8 is a flowchart illustrating a candidate region determination process described with reference to FIGS.

Referring to FIG. 8, in step S121, the terminal position estimation apparatus may set the index k to 1. The index k is an index indicating a pair of base stations (BS1, BS2, BS3, BS4).

In step S122, the terminal position estimation apparatus may select the k-th pair of base stations. Depending on the k-index value, the combination of base stations selected may vary.

In step S123, the terminal position estimation apparatus may calculate a vertical bisector between the kth base stations. For example, when k = 1, the terminal position estimation apparatus can calculate the vertical bisector L12 between the first base station BS1 and the second base station BS2. , and k = 2, the terminal position estimation apparatus can calculate the vertical bisector L24 between the second base station BS2 and the second base station BS4. , and k = 3, the terminal position estimation apparatus can calculate the vertical bisector L23 between the second base station BS2 and the third base station BS3.

In step S124, the terminal position estimation apparatus may determine the kth candidate region based on the time stamp values acquired from the kth pair of base stations. The terminal position estimation apparatus can determine a region with a smaller time stamp value among kth base stations as a kth candidate region. If k is 2 or more, the terminal position estimation apparatus can determine the kth candidate region in the (k-1) th candidate region. The kth candidate region may be smaller than or equal to the (k-1) th candidate region.

과 비교할 수 있다. 여기서, n은 단말(UE)로부터 신호를 수신한 기지국들의 개수를 의미한다. 도 3 내지 도 7에서 나타낸 바와 같이 4개의 기지국들(BS1, BS2, BS3, BS4)을 고려하는 경우, n=4일 수 있다. n=4인 경우, 가능한 기지국 쌍들의 조합의 개수가 6개일 수 있다. 따라서, 단말 위치 추정 장치는, k 값이 6보다 작은지 여부를 판단할 수 있다.In step S125, the terminal position estimation apparatus calculates k

. Here, n denotes the number of base stations receiving a signal from the UE. When considering four base stations (BS1, BS2, BS3, BS4) as shown in Figs. 3 to 7, n = 4. When n = 4, the number of combinations of possible base station pairs may be six. Therefore, the terminal position estimation apparatus can determine whether or not the value of k is smaller than 6. [

보다 작은 경우, 모든 경우의 기지국 쌍들이 고려되지 않았으므로, 단말 위치 추정 장치는, k 값을 1만큼 증가 시킬 수 있다. 그리고, 단말 위치 추정장치는 S122 단계에서, 이전까지 고려되지 않았던 다른 쌍의 기지국들을 선택할 수 있다. 단말 위치 추정 장치는 상술한 바와 같이, S123 단계 및 S124 단계를 반복할 수 있다.The value of k

, The terminal position estimation apparatus can increase the value of k by 1 since base station pairs in all cases are not considered. In step S122, the terminal position estimation apparatus may select another pair of base stations that have not been considered before. The terminal position estimation apparatus can repeat steps S123 and S124 as described above.

보다 작지 않은 경우, 모든 경우의 기지국 쌍들이 고려되었으므로, 단말 위치 추정 장치는, k번째 후보 영역을 최종 후보 영역으로 결정하고, 후보 영역을 결정하는 과정을 종료할 수 있다.The value of k

, The terminal position estimation apparatus may determine the kth candidate region as the final candidate region and terminate the process of determining the candidate region.

Referring back to FIG. 2, in step S130, the UE location estimation apparatus may determine a location coordinate of a UE in a candidate region. The terminal location estimation apparatus can determine the location coordinates of the terminal UE based on the time stamp values obtained from the base stations BS1, BS2, BS3, and BS4. The terminal position estimation apparatus can select at least one of the candidate coordinates in the finally determined candidate region based on the time stamp values.

9 is a conceptual diagram illustrating an example in which the terminal position estimation apparatus selects candidate coordinates within a candidate region.

Referring to FIG. 9, the terminal location estimation apparatus may consider candidate coordinates in the finally determined candidate region. The candidate region can be determined by the method described with reference to Figs. A plurality of candidate coordinates may exist in the candidate region. The terminal position estimation apparatus may store the difference of the time stamp values corresponding to each of the candidate coordinates. The terminal location estimation apparatus can store the difference of the time stamp values corresponding to the candidate coordinates in consideration of the distance between the candidate coordinates and the base stations BS1, BS2, BS3, BS4.

For example, with respect to the candidate coordinate Pn, the terminal position estimation apparatus can calculate the distance between the coordinate Pn and the first base station BS1. The terminal location estimation apparatus can calculate the distance between the coordinate Pn and the second base station BS2. The terminal position estimation apparatus calculates the difference tPn1-tPn2 of the time stamp values from the difference between the coordinate Pn and the distance between the first base station BS1 and the coordinate Pn and the distance between the second base station BS2, Can be stored. Here, tPn1-tPn2 denotes a difference between the time stamp value of the first base station BS1 and the time stamp value of the second base station BS2 when a signal is transmitted at the coordinate Pn.

Similarly, the terminal location estimation apparatus can calculate the difference in timestamp values of other base stations in consideration of the coordinates Pn and the positions of the base stations BS1, BS2, BS3, and BS4. In FIG. 9, tPn2-tPn3 denotes the difference between the time stamp value of the second base station BS2 and the time stamp value of the third base station BS3 at the coordinate Pn. tPn3-tPn4 means the difference between the time stamp value of the third base station (BS3) and the time stamp value of the fourth base station (BS4) at the coordinate Pn. tPn1-tPn3 indicates the difference between the time stamp value of the first base station BS1 and the time stamp value of the third base station BS3 at the coordinate Pn. tPn1-tPn4 denotes a difference between the time stamp value of the first base station BS1 and the time stamp value of the fourth base station BS4 at the coordinate Pn. tPn2-tPn4 denotes the difference between the time stamp value of the second base station BS2 and the time stamp value of the fourth base station BS4 at the coordinate Pn.

The terminal position estimation apparatus can calculate the difference of the time stamp values of the base stations for each of the candidate coordinates and store the calculation result. The terminal position estimation apparatus can store the candidate coordinates and the difference of the time stamp values assigned to the candidate coordinates in a lookup table format.

The terminal location estimation apparatus can calculate the difference of the time stamp values acquired from the base stations BS1, BS2, BS3, and BS4. For example, the terminal location estimation apparatus can calculate the difference of the time stamp values acquired from the base stations BS1, BS2, BS3, and BS4 as shown on the right side of FIG. t1 denotes a time stamp value obtained from the first base station BS1, t1 denotes a time stamp value obtained from the first base station BS1, t2 denotes a time stamp value obtained from the second base station BS2 T3 denotes a time stamp value obtained from the third base station BS3, and t4 denotes a time stamp value obtained from the fourth base station BS4.

The terminal location estimation apparatus can compare the difference of the time stamp values obtained from the base stations BS1, BS2, BS3, and BS4 with the difference of the time stamp values assigned to the candidate coordinates. The terminal location estimation apparatus can select the candidate coordinates to which the difference of the time stamp values close to the difference of the time stamp values acquired from the base stations BS1, BS2, BS3, and BS4 is allocated. The terminal position estimation apparatus can select at least one candidate coordinate. When the terminal location estimation apparatus selects one candidate coordinate, the selected candidate coordinates can be determined as the position coordinates of the terminal UE. As another example, when the terminal position estimation apparatus selects a plurality of candidate coordinates, the coordinates between the plurality of candidate coordinates can be determined as the position coordinates of the terminal UE. Illustratively, the terminal position estimation apparatus can determine the center of the selected plurality of candidate coordinates as the position coordinates of the terminal UE.

FIG. 10 is a flowchart illustrating a process of performing step S130 of FIG.

Referring to FIG. 10, in step S131, the terminal position estimation apparatus can compare the difference of the time stamp values assigned to the candidate coordinates and the difference of the time stamp values obtained from the base stations BS1, BS2, BS3, and BS4. Based on the comparison result, the terminal position estimation apparatus can select the candidate coordinates.

In step S132, the terminal position estimation apparatus may determine whether or not candidate coordinates exist.

If the terminal location estimation apparatus fails to select the candidate coordinates, the terminal position estimation apparatus can determine the position coordinates of the terminal UE from the vertex coordinates of the finally determined candidate region in step S133. For example, in the case of the triangular candidate region shown in FIG. 9, the midpoint between the three vertexes can be determined as the position coordinates of the UE.

If there are candidate coordinates, the terminal position estimation apparatus can determine whether there are one or more candidate coordinates in step S134.

If there is one candidate coordinate, the terminal position estimation apparatus may determine the selected candidate coordinates as the position coordinates of the terminal UE in step S135.

If there are a plurality of candidate coordinates, the terminal position estimation apparatus can determine the position coordinates of the terminal UE from a plurality of candidate coordinates in step S136. For example, the terminal location estimation apparatus may determine a midpoint between a plurality of candidate coordinates as a location coordinate of a terminal UE.

The apparatus and method for estimating a terminal location according to exemplary embodiments of the present invention have been described above with reference to FIG. 1 through FIG. According to the above-described embodiments, the position of the UE can be estimated by the TDoA scheme. Further, by setting the candidate region and determining the position coordinates of the terminal within the candidate region, it is possible to reduce the calculation amount and time required for estimating the position of the terminal.

The methods according to the present invention can be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the computer readable medium may be those specially designed and constructed for the present invention or may be available to those skilled in the computer software.

Examples of computer readable media include hardware devices that are specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by the compiler 1, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate with at least one software module to perform the operations of the present invention, and vice versa.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

Claims (20)

A method for estimating a position of a terminal in a communication network,
Obtaining timestamp values indicating a time when a plurality of base stations received a signal from the terminal;
Determining a candidate region for a location of the terminal based on the location of the base stations and the timestamp values;
And determining the position coordinates of the terminal based on the time stamp values in the candidate region. The method according to claim 1,
Wherein the step of determining the candidate region comprises:
Selecting a first pair of base stations from among the base stations and determining a first candidate region based on time stamp values received from the first pair of base stations. The method of claim 2,
Wherein a boundary of the first candidate region is determined by a vertical bisector between the first pair of base stations. The method of claim 2,
Wherein the step of determining the candidate region comprises:
Selecting a second pair of base stations different from the first pair among the base stations and determining a second candidate region within the first candidate region based on time stamp values received from the second pair of base stations A method for estimating a location of a terminal. The method of claim 4,
Wherein a boundary of the second candidate region is determined by a vertical bisector between the second pair of base stations. The method of claim 2,
Wherein the step of determining the candidate region comprises:
k th candidate base stations based on time stamp values received from the kth pair of base stations,
kth candidate region is determined based on time stamp values received from the (k + 1) -th pair of base stations.
(k is

Less than or equal to a natural number, and n is the number of base stations) The method according to claim 1,
Wherein the step of determining the location coordinates of the terminal comprises:
And determining at least one of a plurality of candidate coordinates in the candidate region based on the time stamp values. The method of claim 7,
Wherein the step of determining the location coordinates of the terminal comprises:
And comparing the difference between the time stamp values corresponding to each of the plurality of candidate coordinates and the time stamp value received from the base stations to determine the position coordinates of the terminal. The method of claim 8,
Wherein a difference between timestamp values corresponding to each of the plurality of candidate coordinates is determined by each of the candidate coordinates and a distance between the base stations. The method of claim 8,
Wherein the step of determining the location coordinates of the terminal comprises:
And determining one of the plurality of candidate coordinates as the position coordinates of the terminal. The method of claim 8,
Wherein the step of determining the location coordinates of the terminal comprises:
Selecting two or more candidate coordinates among the plurality of candidate coordinates and determining coordinates between the two or more candidate coordinates as the position coordinates of the terminal. An apparatus for estimating a terminal location in a communication network,
A processor; And
Wherein at least one instruction executed through the processor includes a memory,
Wherein the at least one instruction comprises:
The method includes obtaining a time stamp value indicating a time when a plurality of base stations received a signal from the terminal, determining a candidate region for the position of the terminal based on the positions of the base stations and the time stamp values, And determining the position coordinates of the terminal based on the time stamp values. The method of claim 12,
Wherein the at least one instruction comprises:
And selects a first pair of base stations from among the base stations and determines a first candidate region based on time stamp values received from the first pair of base stations. 14. The method of claim 13,
Wherein a boundary of the first candidate region is determined by a vertical bisector between the first pair of base stations. 14. The method of claim 13,
Wherein the at least one instruction comprises:
Selecting a second pair of base stations different from the first pair among the base stations and determining a second candidate region within the first candidate region based on time stamp values received from the second pair of base stations Wherein the terminal position estimating means performs the terminal position estimating. 16. The method of claim 15,
Wherein a boundary of the second candidate region is determined by a vertical bisector between the second pair of base stations. 14. The method of claim 13,
Wherein the at least one instruction comprises:
k th candidate base stations based on time stamp values received from the kth pair of base stations,
1 th candidate region based on time stamp values received from the k + 1 < th > pair of base stations, and selects a (k + 1) .
(k is

Less than or equal to a natural number, and n is the number of base stations) The method of claim 12,
Wherein the at least one instruction comprises:
And to determine at least one of a plurality of candidate coordinates in the candidate region based on the time stamp values. 19. The method of claim 18,
Wherein the at least one instruction comprises:
And comparing the difference between the time stamp values corresponding to each of the plurality of candidate coordinates and the time stamp value received from the base stations to determine the position coordinates of the terminal. The method of claim 19,
Wherein a difference between timestamp values corresponding to each of the plurality of candidate coordinates is determined by each of the candidate coordinates and a distance between the base stations.

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