KR20110035983A - Method and apparatus for positioning - Google Patents

Abstract

PURPOSE: A wireless location measuring method and device thereof are provided to obtain an accurate location measuring result from a satellite signal receiving shadow area. CONSTITUTION: A signal receiving unit(510) receives signals from transmitters. An electric wave delay tap determining unit(520) determines the electric wave delay taps of the transmitters. A distance calculating unit(530) calculates the distance between each transmitter and each receiver. A weighted value calculating unit(540) uses an electric wave delay tap. The weighted value of each transmitter is calculated. A location estimating unit(550) adjusts a distance using a weighted value and estimates an area where circles which are remote as much as the final distance from each transmitter are overlapped as the location of a receiver.

Description

Wireless positioning method and device {METHOD AND APPARATUS FOR POSITIONING}

The present invention relates to a wireless positioning method and apparatus, and more particularly to a method and apparatus for measuring the position of the terminal based on the type of propagation delay.

The wireless positioning technology is a technology for measuring the location of a terminal in a wireless communication system. Recently, the field of service has been expanded along with an increasing demand for a location based service (LBS). In particular, as the demand for a technology capable of identifying a user's situation or location and provide a suitable service to a user increases, interest in wireless positioning technology is increasing.

GPS (Global Positioning System), a typical wireless positioning technology, provides high accuracy positioning results, but the indoor terminal cannot receive the GPS signal, and only the terminal equipped with the GPS receiver can receive the GPS signal. have.

Accordingly, as another radio positioning technology, a received signal strength indicator (RSSI) method and a time difference of arrival (TDOA) method are considered. The RSSI method is a method of acquiring location information using the strength of a received signal. According to the RSSI method, although the structure is simple, the position information can be easily obtained, but there is a problem that a large error occurs due to a path loss.

The TDOA method is a method of acquiring position information by using a difference in arrival time of a signal. According to the TDOA method, time synchronization between the receiver and the transmitter is not necessary, but time synchronization between the transmitters is required.

The wireless positioning techniques described above, such as the GPS, RSSI method, and TDOA method, cannot all provide accurate positioning results in non-line of Sight (NLOS) environments or in poor channel conditions. there is a problem. Accordingly, there is a need for a method of providing accurate positioning results by reflecting a signal propagation environment.

The technical problem to be achieved by the present invention is to provide a radio positioning method and apparatus in consideration of the type of propagation delay. In particular, an object of the present invention is to provide a wireless positioning method and apparatus for minimizing positioning error in an NLOS environment.

In a radio positioning method of a receiver according to an aspect of the present invention, receiving signals from a plurality of transmitters, determining propagation delay taps of the plurality of transmitters received from the plurality of transmitters, respectively, between the receiver and each transmitter Calculating a distance of the transmitter, calculating a weight of each transmitter using the propagation delay tab, adjusting the distance using the weight, and between the receiver and each transmitter with respect to each transmitter. Estimating the area where the circles separated by the adjusted distance overlap each other as the position of the receiver.

In a radio positioning method of a receiver according to another aspect of the present invention, receiving signals from a plurality of transmitters, determining propagation delay taps of the plurality of transmitters received from the plurality of transmitters, and propagation delays of the respective transmitters. Calculating a distance between the receiver and each transmitter using the arrival time of the propagation delay tap first reached among the taps, and determining the position of the receiver using the distance and the delay spread value. .

A radio positioning apparatus of a receiver according to an aspect of the present invention includes a signal receiver for receiving signals from a plurality of transmitters, a propagation delay tap determination unit for determining propagation delay taps of the plurality of transmitters received from the plurality of transmitters, respectively. A distance calculator configured to calculate a distance between a receiver and each transmitter, a weight calculator configured to calculate a weight of each transmitter using the propagation delay tab, and adjust the distance using the weights, And a position determiner for estimating a region where circles separated by an adjusted distance between the receiver and each transmitter overlap each other as the position of the receiver.

According to a wireless positioning method and apparatus according to an embodiment of the present invention, positioning errors in an NLOS environment can be minimized. Therefore, accurate positioning results can be obtained using wireless communication even in areas where satellite reception is difficult.

1A to 1D are diagrams illustrating types of propagation delay tabs.
2 is a diagram illustrating an example of a radio positioning method of a receiver.
3 and 4 are diagrams illustrating delay spreading with distance in a propagation delay tap indicating an NLOS environment.
5 is a wireless positioning apparatus according to an embodiment of the present invention, Figure 6 is a wireless positioning method according to an embodiment of the present invention.
7 is a diagram illustrating a method for estimating the position of a receiver by a radio positioning apparatus according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, except to exclude other components unless otherwise stated.

In the present specification, a terminal is a mobile station (MS), a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), a user equipment (User Equipment). It may also refer to a user equipment (UE), an access terminal (AT), and the like, and may include all or some functions of a terminal, a mobile station, a mobile terminal, a subscriber station, a portable subscriber station, a user device, an access terminal, and the like. .

In the present specification, a base station (BS) is a radio access station (RAS), a node B (Node B), an advanced node B (evolved NodeB, eNodeB), a base transceiver station (Base Transceiver Station, BTS), MMR (Mobile Multihop Relay) -BS and the like, and may include all or part of the functions of a base station, a radio access station, a NodeB, an eNodeB, a base transceiver station, an MMR-BS, and the like.

Hereinafter, a wireless positioning method and apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1A to 1D are diagrams illustrating types of propagation delay tabs.

The propagation delay tap refers to a form in which a signal transmitted from a transmitter is delayed spread in a multipath environment. If there is a topographic obstruction between the transmitter and receiver, multiple paths are formed due to reflection or diffraction of the signal by the obstruction. Thus, one signal transmitted from the transmitter is delay spread through multiple paths.

Referring to FIG. 1A, the signal strength of the propagation delay tap 10 that reaches the receiver first is the strongest. If there is no obstruction between the transmitter and the receiver, the signal transmitted from the transmitter can reach the receiver with high signal strength in a short time. Thus, the type of FIG. 1A may be a propagation delay type close to a line of sight (LOS) environment.

Referring to FIG. 1B, the signal strength of the second propagation delay tab 21 reaching the receiver is the strongest, and the signal strength of the first propagation delay tab 20 reaching the receiver is greater than the signal strength of the propagation delay tab 21. weak.

Referring to FIG. 1C, the signal strength of the third propagation delay tap 31 reaching the receiver is the strongest, and the signal strength of the propagation delay tap 30 reaching the earliest is greater than the signal strength of the propagation delay tap 31. weak.

Referring to FIG. 1D, the signal strength of the propagation delay tap 41 reaching the receiver is the strongest, and the signal strength of the propagation delay tap 40 reaching the earliest is weaker than the signal strength of the propagation delay tap 41. .

The more similar the type of propagation delay tap is to the type of FIG. 1A, the closer the environment between the transmitter and receiver is to the LOS environment. In addition, as the type of the propagation delay tap is similar to that of FIG. 1D, i.e., the arrival time of the propagation delay tap having the strongest signal strength is delayed, the environment between the transmitter and the receiver is non-line of Sight Close to

2 is a diagram illustrating an example of a radio positioning method of a receiver.

Referring to FIG. 2, the receiver 100 estimates the position of the receiver 100 using reference signals for radio positioning transmitted by a plurality of transmitters, for example, the transmitters 200, 300, and 400. It is assumed that the receiver 100 knows the positions of the transmitters 200, 300, and 400.

The receiver 100 uses the arrival times of the propagation delay taps that are received first among the propagation delay taps of the reference signals received from the transmitters 200, 300, and 400, respectively. Calculate the distance between the centers, centering each transmitter (200, 300, 400), the circle (X, Y, Z where the calculated distance between each transmitter (200, 300, 400) and the receiver 100 is a radius ). The receiver 100 may estimate an area where the circles X, Y, and Z overlap each other as the position of the receiver 100.

Meanwhile, as the propagation environment between the receiver and the transmitter is closer to the LOS environment, the propagation delay tap arrives at the receiver faster, and the propagation delay tap arrives at the receiver later when the propagation delay is closer to the NLOS environment. Therefore, as shown in FIG. 2, if the influence of the propagation environment is not taken into account when calculating the distance between the receiver and the transmitter using the arrival time of the propagation delay tap, a large error may occur in the positioning of the receiver. That is, when the propagation environment between the receiver and each transmitter is an ideal LOS environment, the circles centered on each transmitter meet at one point. On the other hand, when the propagation environment between the receiver and the transmitter is an NLOS environment, the arrival time of the first propagation delay tap of the transmitter is delayed compared to the LOS environment, and the distance between the receiver and each transmitter is calculated longer than the actual distance. The area where the circles around the transmitter overlap is widened.

3 and 4 are diagrams illustrating delay spreading with distance in a propagation delay tap indicating an NLOS environment.

3 and 4, the propagation delay taps 51 and 61 having the strongest signal strength are not the propagation delay taps 50 and 60 that arrive first. From this, it can be seen that the propagation environment between the receiver and the transmitter is an NLOS environment.

On the other hand, when the difference between the arrival time of the propagation delay taps 50, 60 reaching the earliest arrival time and the arrival time of the propagation delay taps 52, 62 reaching the latest time is defined as the delay spread value, the delay spread value of FIG. Is less than the delay spread value of FIG. As the distance between the receiver and the transmitter increases, the delay spread value increases, which means that the distance between the receiver and the transmitter for the propagation delay tap of FIG. Hereinafter, a method of determining the exact position of the receiver by reflecting the delay spread value will be described.

5 is a wireless positioning apparatus according to an embodiment of the present invention, Figure 6 is a wireless positioning method according to an embodiment of the present invention. The radio location device may be part of the receiver. It is assumed that the radio location device knows the position of the peripheral transmitter.

Referring to FIG. 5, the wireless positioning apparatus 500 includes a signal receiver 510, a propagation delay tap determiner 520, a distance calculator 530, a weight calculator 540, and a position estimator 550. Include.

5 and 6, the signal receiver 510 receives signals transmitted from a plurality of transmitters (S600). The signal transmitted from the transmitter may be, for example, a reference signal for positioning. Hereinafter, the signal receiving unit 510 will be described as an example of receiving reference signals for positioning from a plurality of transmitters, respectively.

The propagation delay tap determination unit 520 determines a propagation delay tap for signals transmitted from the plurality of transmitters (S610). For example, the propagation delay tap determination unit 520 determines the arrival time of the propagation delay tap that is reached first for each transmitter, the arrival time of the propagation delay tap that is reached latest, and the arrival time of the propagation delay tap having the strongest signal strength. can do. The propagation delay tap determination unit 520 may further determine a propagation environment based on the propagation delay tap. For example, the propagation delay tap determination unit 520 selects the propagation delay tap having the strongest signal strength from the propagation delay tap of each transmitter, and when the selected propagation delay tap is the propagation delay tap that reaches the earliest, the propagation environment of the transmitter. It is determined that the LOS environment. On the other hand, if the selected propagation delay tap is not the first propagation delay tap, it is determined that the propagation environment of the transmitter is the NLOS environment.

The distance calculator 530 calculates a distance between the transmitter and the receiver (S620). The distance between the transmitter and the receiver may be calculated using the arrival time of the propagation delay tap that is reached first among the propagation delay taps of each transmitter.

On the other hand, the weight calculation unit 540 calculates the weight of each transmitter using the propagation delay tap of each transmitter (S630). For example, the weight of each transmitter may be calculated using Equation 1.

Here, D _i denotes a delay spread value of the transmitter i, and N denotes the total number of transmitters transmitting the reference signal to the receiver or the number of transmitters in the NLOS environment among the transmitters transmitting the reference signal to the receiver. The delay spread value means the difference between the arrival time of the propagation tap that reached the earliest time and the arrival time of the propagation delay tap that reached the latest. As another example, the weight of each transmitter may be calculated using Equation 2.

Here, S _i means the signal strength of the propagation delay tap of the transmitter i. That is, the weight may be calculated using the delay spread value of each transmitter and the signal strength of the propagation delay tap.

Next, the position estimator 550 adjusts the distance between the receiver and each transmitter by using the weight of each transmitter, and estimates the position of the receiver (S640). For example, the position estimator 550 may reduce the distance of each transmitter calculated in step S620 by a weight ratio. The position estimator 550 may estimate, as the position of the receiver, an area in which circles separated by the distance between the receiver and each transmitter overlap each other with respect to each transmitter. A detailed method of adjusting the distance between the receiver and each transmitter and estimating the position of the receiver will be described later.

7 is a diagram illustrating a method for estimating the position of a receiver by a radio positioning apparatus according to an embodiment of the present invention.

Referring to FIG. 7, it is assumed that the receiver 600 knows the position of each transmitter 700, 800, 900.

The radio positioning apparatus uses the arrival times of the propagation delay taps that are received first among the propagation delay taps of the reference signals received from the transmitters 700, 800, and 900, respectively. The distance between the transmitters 700, 800, and 900, and calculate the distance between the transmitters 700, 800, 900 and the receiver 600 to be a radius (X, Y, Z). ).

On the other hand, the wireless positioning device calculates the weight of each transmitter, and reduces the distance between each transmitter (700, 800, 900) and the receiver 600 according to the ratio of the weight.

Distance adjustment according to the weight ratio may be repeated until each transmitter is centered and the circles whose radius is the adjusted distance between the receiver and each transmitter converge at one point. Or it may be repeated until the area of the area where the circles overlap with each other is less than a predetermined range.

In the foregoing description, for convenience of description, it is assumed that a receiver receives reference signals for positioning from three transmitters, but the technical spirit of the present invention is not limited thereto. The receiver may receive reference signals for positioning from three or more transmitters, and perform positioning based on the received reference signals.

As such, when the radio positioning is performed based on the type of the propagation delay tap, it is possible to reduce the error of the radio positioning occurring when the radio environment is the NLOS environment.

The embodiments of the present invention described above are not only implemented through the apparatus and the method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (14)

In the radio positioning method of the receiver,
Receiving signals from a plurality of transmitters,
Determining propagation delay taps of the plurality of transmitters respectively received from the plurality of transmitters,
Calculating a distance between the receiver and each transmitter,
Calculating a weight of each transmitter using the propagation delay tap;
Adjusting the distance using the weights, and
Estimating, as the position of the receiver, an area in which circles separated by the adjusted distance between the receiver and each transmitter with respect to each transmitter overlap each other. The method of claim 1,
And the weight is calculated using a delay spread value of each transmitter. The method of claim 2,
The weighting method is calculated using the signal strength of the propagation delay tap of each transmitter. The method of claim 2,
Wherein the delay spread value of each transmitter is a difference between the arrival time of the propagation tap that is reached first among the propagation delay taps of each transmitter and the arrival time of the propagation tap that is reached the latest. The method of claim 1,
The step of calculating the distance,
And calculating the distance using the arrival time of the propagation delay tap that is reached first of the propagation delay taps of each transmitter. In the radio positioning method of the receiver,
Receiving signals from a plurality of transmitters,
Determining propagation delay taps of the plurality of transmitters respectively received from the plurality of transmitters,
Calculating a distance between the receiver and each transmitter using the arrival time of the propagation delay tap which is reached first among the propagation delay taps of each transmitter, and
Determining the position of the receiver using the distance and the delay spread value. The method of claim 6,
Wherein the delay spread value is a difference between the arrival time of the propagation tap first reached among the propagation delay taps of each transmitter and the arrival time of the latest propagation delay tap reached last. The method of claim 7, wherein
Determining the position of the receiver,
Calculating a weight of each transmitter using the delay spread value;
Correcting the distance using the weight of each transmitter, and
And determining the overlapping area as the position of the receiver when the area where the circles spaced apart by the corrected distance overlap each other about the transmitters is narrowed to a predetermined range or less. The method of claim 8,
The propagation delay weight is calculated by further using the signal strength of the propagation delay tap of each transmitter. The method of claim 8,
The correcting step,
And reducing the distance between the receiver and each transmitter by a ratio of propagation delay weights of each transmitter. The method of claim 10,
Reducing the distance is repeated until the overlapping area is narrowed below the predetermined range. In the radio positioning device of the receiver,
A signal receiver for receiving signals from a plurality of transmitters,
A propagation delay tap determination unit for determining propagation delay taps of the plurality of transmitters respectively received from the plurality of transmitters;
Distance calculation unit for calculating the distance between the receiver and each transmitter,
A weight calculator configured to calculate a weight of each transmitter using the propagation delay tap;
And a positioning unit for adjusting the distance by using the weight and estimating an area where circles separated by an adjusted distance between the receiver and each transmitter overlap each other with respect to each transmitter as the position of the receiver. Device. The method of claim 12,
And the distance calculator calculates the distance using the arrival time of the propagation delay tap that is reached first among the propagation delay taps of the transmitters. The method of claim 12,
And the weight calculator calculates the weight using a delay spread value of each transmitter.

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