KR101835975B1 - Location server, user equipment, and method for positioning user equipment in a wireless communication system - Google Patents

Abstract

A method for measuring a position of a terminal in a wireless communication system is provided. The method includes the steps of determining a PRS reception time difference (RSTD) between a first base station and a second base station based on a first positioning reference signal (PRS) having a first bandwidth, Receiving information about an RSTD between a first base station and a second base station based on a second PRS having a second bandwidth different from the first bandwidth, Based on the information about the RSTD between the first base station and the second base station and the information about the RSTD between the first base station and the second base station measured based on the second PRS, 0.0 > RSTD. ≪ / RTI > Therefore, it is possible to reduce the quantization error of the PRS reception without expanding the bandwidth and changing the RSTD reporting table.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for measuring a position of a terminal in a wireless communication system, a location server and a terminal,

The present invention relates to a wireless communication system, and more particularly, to a method, a location server, and a terminal for measuring a position of a terminal in a wireless communication system.

In recent years, the mobile communication industry has attracted much attention to mobile location positioning technology for location based service (LBS) that provides specific information according to user's changed location to wireless Internet users. For example, as the demand for high-quality location-based services that can check information of nearby facilities such as a cash register or a restaurant, location information of a discount gas station, and real-time traffic situation is increasing, There is a growing need for more accurate location positioning techniques. Recently, the 3GPP standardization group has been actively discussing the improved location locating technology in the harsh environments in which indoor and outdoor environments and many high-rise buildings are present. In 3GPP Release 9, OTDOA based location locating technology is adopted as a standard have.

In addition, as the number of users using portable wireless terminals such as smart phones, tablet PCs, and wearable devices has increased recently, applications that provide various types of services other than location based services have been developed, And is rapidly increasing. Accordingly, in order to solve the battery power problem which is rapidly consumed, researches on other types of wireless charging methods other than the existing wired and auxiliary batteries are under way. In particular, wireless energy harvesting technology that collects energy from RF (Radio Frequency) electromagnetic waves transmitted by peripheral communication equipment such as a base station or AP (Access Point), recharges the battery of the wireless terminal and reuses the charged energy for communication Researches are being actively conducted.

RF energy harvesting is a technology in which a communication terminal receives and transmits a signal having a specific size of power on a frequency by transmitting it to energy. Here, in order to increase the harvesting efficiency of the wireless terminal, a downlink beamforming technique may be applied to an antenna installed in a communication device to transmit energy. As shown in FIG. 1, in the mobile communication system, beamforming is a technique of a smart antenna, in which an antenna installed in a communication equipment such as the base station 10 concentrates radio waves in a specific direction and emits strong radiation. Therefore, in the wireless power transmission system, the signal transmitted by the antenna to which the beamforming technique is applied is received only by the terminals 20-1 and 20-3 of the user who wishes to perform the harvesting, and is strong in the signal interference There are characteristics.

In order to increase the efficiency of RF energy harvesting based on beamforming technology, a communication device such as the base station 10 transmits the position of the wireless terminals 20-1, 20-2, 20-3, and 20-4 Or Direction Of Arrival (DOA) of the signal. As shown in FIG. 1, the beamforming-based base station 10 concentrates and transmits a signal in a direction in which specific terminals 20-1 and 20-3 are located. Therefore, when signals are transmitted in different directions, they are greatly exposed to interference or noise Energy harvesting can be difficult. Therefore, the accurate position information of the specific terminals 20-1 and 20-3 to receive the RF signal through the beam forming technique can improve the performance and efficiency of RF energy harvesting. To this end, Positioning techniques can be considered.

International Publication No. PCT / US2014 / 020598 ("Differential ultra-wideband indoor positioning," M. KHALAF-ALLAH, published March 5, 2014)

 M. Thorpe, M. Kottkamp, A. Rossler, and J. Schutz, " LTE Location Based Services Technology Introduction, " Rohde & Schwarz,  3GPP TR 37.857 v13.0.0, "Study on Indoor Positioning Enhancements," published in September 2015.  R1-153989, "OTDOA Performance for Intra-Band Contiguous CA Operation," Intel, 3GPP TSG RAN WG1 Meeting # 82, Beijing, China,  B. Yang, K. B. Letaief, R. S. Cheng, and Z. Cao, "Timing Recover for OFDM Transmission," IEEE Journal on Selected Areas in Communications, vol. 18, no. 11, pp. 2278-2291, November 2000.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to reduce quantization error caused by sampling of a Positioning Reference Signal (PRS) in a wireless communication system, And a method for measuring the same.

According to another aspect of the present invention, there is provided a location server and a terminal capable of increasing the accuracy of location positioning by reducing a quantization error caused by sampling of a positioning reference signal (PRS) .

It is to be understood, however, that the technical scope of the present invention is not limited to the disclosed embodiments, but may be variously modified without departing from the spirit and scope of the present invention.

According to another aspect of the present invention, there is provided a method for measuring a position of a terminal in a wireless communication system, the method comprising: receiving a first positioning reference signal having a first bandwidth, Receiving information on a PRS reception time difference (RSTD) between the first base station and the second base station based on the first bandwidth and the second bandwidth, the second bandwidth being different from the first bandwidth; Receiving information about the RSTD between the first base station and the second base station, measured based on a second PRS; receiving information about the RSTD between the first base station and the second base station based on the first PRS; And determining a final RSTD between the first base station and the second base station based on information on the RSTD between the first base station and the second base station measured based on the second PRS It can include.

According to an aspect of the present invention, the sampling point interval of the first PRS and the second PRS may be different according to the respective bandwidth sizes of the first PRS and the second PRS.

According to an aspect, determining the final RSTD between the first and second base stations may include detecting a first sampling interval including the detected sampling point of the first PRS and a detected sampling point of the second PRS And determining the final RSTD by considering the midpoint of the common interval as the reception time of the PRS from the first base station.

According to an aspect, the method includes receiving information about RSTD between a first base station and a third base station, determining a final RSTD between the first base station and the second base station, and a RSTD between the first base station and the third base station, And determining the location of the terminal based on the information.

According to an aspect, the method may be performed by an Evolved Serving Mobile Location Center (E-SMLC).

According to an aspect, the method further includes receiving information about the RSTD between the first base station and the second base station, measured based on a third PRS having a third bandwidth different from the first bandwidth and the second bandwidth Wherein determining the final RSTD comprises: determining information about the RSTD between the first base station and the second base station based on the first PRS, determining information about the RSTD between the first base station and the second base station, The final RSTD may be determined based on RSTD information between the base stations and the RSTD between the first base station and the second base station measured based on the third PRS.

According to another aspect of the present invention, there is provided a location server operating in a wireless communication system, including: a radio frequency (RF) unit for transmitting and receiving a radio signal; a processor operatively coupled to the RF unit; Wherein the processor calculates a PRS reception time difference (RSTD) between the first base station and the second base station based on a first positioning reference signal (PRS) having a first bandwidth, Receiving information about the RSTD between the first base station and the second base station based on a second PRS having a second bandwidth different from the first bandwidth; Information on the RSTD between the first base station and the second base station measured based on the PRS and information on the RSTD between the first base station and the second base station, Based on information about the RSTD between the first base station and the second base station.

According to an aspect of the present invention, the sampling point interval of the first PRS and the second PRS may be different according to the respective bandwidth sizes of the first PRS and the second PRS.

According to an aspect, determining the final RSTD between the first base station and the second base station comprises determining a first RSTD between the first and second base stations, wherein the first sampling interval includes the detected sampling point of the first PRS, Determining a common interval of the second sampling interval and determining the final RSTD by considering the midpoint of the common interval as the reception time of the PRS from the first base station.

According to an aspect, the processor is configured to receive information about the RSTD between a first base station and a third base station, to determine a final RSTD between the first base station and the second base station, and information on the RSTD between the first base station and the third base station Based on the location information of the terminal, the location of the terminal.

According to an aspect, the location server may be an Evolved Serving Mobile Location Center (E-SMLC).

According to an aspect, the processor is configured to receive information about the RSTD between the first base station and the second base station, measured based on a third PRS having a third bandwidth different from the first bandwidth and the second bandwidth Wherein determining the final RSTD comprises: determining information about the RSTD between the first base station and the second base station measured based on the first PRS, information about the RSTD between the first base station and the second base station measured based on the second PRS, Based on the information about the RSTD between the first base station and the second base station and the information about the RSTD between the first base station and the second base station measured based on the third PRS.

A method for measuring a position of a mobile station in a wireless communication system according to another embodiment of the present invention for achieving the above object is a method for measuring a position of a terminal, Receiving a second PRS having a first bandwidth and a second bandwidth different from the first bandwidth based on a sensed sampling point of the first PRS and a sensed sampling point of the second PRS; And determining the reception time of the PRS from the first base station.

According to an aspect of the present invention, the sampling point interval of the first PRS and the second PRS may be different according to the respective bandwidth sizes of the first PRS and the second PRS.

According to an aspect, determining the time of receipt of the PRS from the first base station may include determining a time of receipt of the first sampling interval including the sensed sampling point of the first PRS, Determining a common interval of the second sampling interval and determining a center point of the common interval as the reception time of the PRS from the first base station.

According to an aspect of the present invention, the method includes: determining a reception time of a PRS from a second base station and a reception time of a PRS from a third base station; determining a PRS reception time difference between the first base station and the second base station Difference, RSTD), determining RSTD between the first and the third base stations, and transmitting information about the RSTD to the location server.

According to an aspect, the location server may be an Evolved Serving Mobile Location Center (E-SMLC).

According to an aspect, receiving the first PRS and the second PRS further comprises receiving from a first base station a third PRS having a third bandwidth different from the first bandwidth and the second bandwidth, Wherein the step of determining the time of reception of the PRS from the first base station comprises the step of determining the time of reception of the first PRS based on the sensed sampling point of the first PRS, the sensed sampling point of the second PRS, The reception time of the PRS from the base station can be determined.

According to another aspect of the present invention, there is provided a mobile station in a wireless communication system including a radio frequency (RF) unit for transmitting and receiving a radio signal, a processor for functionally combining with the RF unit, Wherein the processor is further configured to receive a first Positioning Reference Signal (PRS) having a first bandwidth from a first base station and a second PRS having a second bandwidth different from the first bandwidth, And to determine a time of receipt of the PRS from the first base station based on the sensed sampling point of the first PRS and the sensed sampling point of the second PRS.

According to an aspect of the present invention, the sampling point interval of the first PRS and the second PRS may be different according to the respective bandwidth sizes of the first PRS and the second PRS.

According to an aspect of the present invention, the determining of the reception time of the PRS from the first base station may include determining a reception time of the PRS from the first base station by using a first sampling interval including the sensed sampling point of the first PRS, Determining a common interval of two sampling intervals and determining the center point of the common interval as the reception time of the PRS from the first base station.

According to an aspect of the present invention, the processor is configured to determine a reception time of the PRS from the second base station and a reception time of the PRS from the third base station, a PRS reception time difference between the first base station and the second base station Difference, RSTD) and determining the RSTD between the first and third base stations, and transmitting information about the RSTD to the location server.

According to an aspect, the location server may be an Evolved Serving Mobile Location Center (E-SMLC).

According to an aspect, receiving the first PRS and the second PRS further comprises receiving from the first base station a third PRS having a third bandwidth different from the first bandwidth and the second bandwidth, Determining the time of receipt of the PRS from the first base station is based on the sensed sampling point of the first PRS, the sensed sampling point of the second PRS, and the sensed sampling point of the third PRS. The reception time of the PRS can be determined.

According to the method for measuring the position of a mobile station in a wireless communication system according to an embodiment of the present invention, even without using a carrier aggregation (CA) or an ELD (Early Late Gate Detector) technique, The quantization error due to the sampling of the signal (Positioning Reference Signal, PRS) can be reduced.

That is, since the quantization error due to the sampling of the PRS can be reduced without performing the bandwidth extension through the CA, the conventional CA-based quantization reduction method can be used only when the intra-band consecutive CA is performed, It is possible to solve the problem that it could not be used in case of band-free continuous CA or inter-band CA.

In addition, since the quantization error can be reduced without newly defining the reporting table of the RSTD, it is possible to easily exhibit the effect of reducing the quantization error even if the definition of the standard document for the RSTD reporting table is not newly established, The quantization error reduction method of the terminal can reduce the quantization error at the terminal end and solve the problem that the location server has no effect of improving the positioning accuracy.

However, the effects of the present invention are not limited thereto, and various modifications may be made without departing from the spirit and scope of the present invention.

1 shows a conceptual diagram of RF energy harvesting and a beam forming technique therefor.
2 shows a conceptual diagram of OTDOA-based position location for a 3GPP LTE system.
Figure 3 shows the quantization error due to time-domain sampling.
4 shows a bandwidth extension method using CA.
FIG. 5 shows a quantization error reduction method using an ELD-based fine time synchronization algorithm.
6 is a conceptual diagram of a new sampling structure according to a combination of sampling points by bandwidth according to an embodiment of the present invention.
7 is an information flow diagram of a variable bandwidth PRS transmission-based quantization error reduction method according to an embodiment of the present invention.
8 is a flowchart of a method for measuring a position of a UE in a wireless communication system according to an embodiment of the present invention.
9 is a detailed flowchart of the final RSTD determination step of FIG.
10 is a block diagram illustrating a configuration of a location server and a terminal according to another embodiment of the present invention.
FIG. 11 shows an operation of sampling point acquisition and quantization error reduction according to an embodiment of the present invention.
12 is a flowchart of a method for determining a position of a UE in a wireless communication system according to another embodiment of the present invention.
13 is a detailed flowchart of the PRS reception time determination step from the first base station in FIG.
14 shows CDF performance of the RSTD estimation error between the conventional technique and the technique according to the present invention.
15 shows the CDF performance of the coordinate error RMSE between the conventional technique and the technique according to the present invention.

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 in this application is used only to describe a specific embodiment and is not intended to limit 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.

The present invention relates to a method and apparatus for estimating a reception time difference (Reference Signal Time Difference) of an Observed Time Difference of Arrival (OTDOA) for positioning a terminal in a wireless communication system such as a 3rd Generation Partnership Project (3GPP) LTE (Long Term Evolution) RSTD), it can be applied to reduce the quantization error caused by the time-domain sampling, which is determined according to the bandwidth size, in receiving the Positioning Reference Signal (PRS).

2 shows a conceptual diagram of OTDOA-based location positioning for a 3GPP LTE system. As shown in Figure 2, is one of the OTDOA positioning method of trilateration based on a terminal (User Equipment, UE) (100 ) at least comprising a serving base station _{(Serving Macro eNB s) (200-1} ) (RSTD) value from the downlink PRS received from the three or more base stations 200-1, 200-2, and 200-3, and transmits the Evolved Serving Mobile Location Center -SMLC) generates two hyperbolic equations based on the RSTD value, and then determines the intersection between two hyperbolas, thereby locating the position of the terminal 100. [ Here, two problems may occur in the process of the terminal 100 measuring the RSTD value and transmitting the information on the RSTD to the location server.

Figure 3 shows the quantization error due to time-domain sampling. As shown in FIG. 3, a quantization error may occur due to time-domain sampling determined according to a bandwidth size at the time of PRS reception in the process of measuring RSTD values by the UE. remind Rx ₁ , Rx ₂ , and Rx _s in Equation 1 represent reception time of PRS, respectively, and e ₁ , e ₂ , and e _s denote quantization error due to time-domain sampling. This leads to inaccurate RSTD _{(1, s )} and RSTD _{( 2, s )} values leading to degradation of positioning performance.

Also, the terminal 100 transmits information on RSTD measured using a reporting table to a location server. The reporting table is defined as a time-domain sampling resolution unit (T _s ) determined according to the bandwidth size have. Therefore, even if the terminal accurately measures the RSTD value, it can cause bottleneck in the positioning performance by the minimum T _s due to the definition of the reporting table.

The current 3GPP LTE standard supports system bandwidths up to 20 MHz. As shown in the following Table 1, the range of the RSTD reporting table corresponding to the 20 MHz bandwidth is -15391 · T _s To 15391 · T _s . The basic unit is 1 · T _s when it is within ± 4096 · T _s according to the range of measured quantization values, and 5 · T _s to be. Here, 1 T _s is 1 / (15000 占 2048) calculated by OFDM (Orthogonal Frequency Division Multiplexing) subcarrier spacing and Fast Fourier Transform (FFT) size on the basis of 20 MHz bandwidth, . In addition, 1 · T _s of the 10 MHz standard defined in the 3GPP LTE is 19.53 m, 1 · T _s of 15 MHz reference is 13.02 m. Therefore, in the OTDOA-based positioning process, the positioning performance may be limited due to the quantization error and the definition of the RSTD reporting table.

Various methods can be used to reduce the quantization error. In Non-Patent Document 2, in the RSTD measurement process for OTDOA-based position location, the quantization error caused by the time-domain sampling determined according to the bandwidth size at the time of PRS reception is reduced, and information on the RSTD based on the RSTD reporting table is transmitted to the location server A recent research trend of 3GPP regarding 'improvement of RSTD accuracy through bandwidth extension' and 'definition of RSTD reporting table suitable for extended bandwidth' is disclosed in order to improve the limited positioning performance in transmission process.

In order to reduce the quantization error, a method of extending the bandwidth of the PRS by utilizing an intra-band contiguous CA may be considered. In this regard, FIG. 4 shows a bandwidth extension method using CA. As shown in FIG. 4 (a), by transmitting PRS through a 40 MHz bandwidth extension using two continuous 20 MHz CCs (Component Carriers), a high resolution sampling interval is obtained to improve the positioning performance . However, in order to apply this, channel space or quasi-collocation between adjacent CCs, or conditions using the same antenna port, should be defined.

As shown in Patent Document 1, a method of reducing the quantization error and improving the indoor positioning performance by utilizing ultra-wideband signal transmission in the time-of-arrival (TOA) based positioning process can be considered. As the bandwidth is wider, the resolution of the time-domain sampling determined by the bandwidth size becomes finer, so the quantization error due to the size of the sampling interval can be reduced and accurate PRS reception time information can be obtained.

Meanwhile, as shown in Non-Patent Document 4, a method of synchronizing a sampling time by estimating a timing offset using an ELD (Early Late Gate Detector) based fine timing synchronization algorithm in an OFDM system can be considered. The ELD algorithm is a typical timing synchronization technique that utilizes the symmetric property of the output signal passed through a matched filter (MF) or a correlator.

In this regard, FIG. 5 shows a quantization error reduction method using an ELD-based fine time synchronization algorithm. For example, as shown in Figure 5, the ideal synchronization (early sample point) preceding the sample point because of the symmetry properties when _{(t = nT 0 - T s} ) and the subsequent sample point (late sample point) (t = nT 0 - T _s ) are the same, and the optimal sampling time will be the midpoint between the two sampling points. In this way, the timing offset and the optimal sampling time can be approximated by the ELD algorithm.

In Equation (2),? Represents a timing offset size between an early gate and a late gate. If? Is 0, the synchronization is correctly performed, and if? Is not 0, a timing offset occurs, and the sampling time will be adjusted and synchronized as shown in FIG. All terminals of the LTE network operate after synchronizing with the reception time of the downlink signal of the base station. Therefore, in terms of timing synchronization, the UE can estimate the quantization error from the received PRS based on the ELD algorithm, and can accurately measure the RSTD from the received PRS.

As described above, a method of expanding the bandwidth of the PRS by utilizing intra-band consecutive CAs in order to reduce the quantization error caused by the time domain sampling determined according to the bandwidth size in the RSTD measurement process of the OTDOA for positioning Non-Patent Document 3) has been proposed, however, there is a problem that an RSTD reporting table suitable for a sampling resolution of an extended bandwidth needs to be newly defined. Likewise, in the case of reducing the quantization error based on the UWB signal (Patent Document 1), a reporting table suitable for a broadband should be newly defined. In addition, since the sampling resolution can not be increased in a non-contiguous CA-only environment as shown in FIGS. 4 (b) and 4 (c), the quantization error can not be reduced. Therefore, in such a communication environment, it is difficult to apply the above-described method.

Meanwhile, a method of estimating a quantization error and measuring an accurate RSTD value based on an ELD-based fine time synchronization algorithm used in an OFDM system (Non-Patent Document 4) is a method in which a terminal transmits information on RSTD to a local server In the process, there is an error again due to the reporting table defined by the sampling resolution unit (Ts) determined according to the bandwidth size. Therefore, there is no improvement in the positioning accuracy in the local server performing the OTDOA operation. Also, when the RSTD reporting table is newly defined in consideration of the accuracy of the ELD algorithm, the greater the accuracy of the RSTD measurement, the larger the size of the reporting table.

On the other hand, according to the method for estimating the position of the terminal in the wireless communication system according to the embodiment of the present invention, in the RSTD measurement process of the OTDOA technique for positioning the terminal, It is possible to improve the positioning performance by efficiently reducing the quantization error caused by the time-domain sampling using the PRSs having different bandwidth sizes supported by the 3GPP LTE standard.

In addition, according to the method for estimating the location of a terminal in a wireless communication system according to an exemplary embodiment of the present invention, a reporting table necessary for transmitting a RSTD to a location server without expanding a bandwidth based on a CA It is possible to obtain a quantization error reduction effect without newly defining it.

New sampling structure based on combination of sampling points by bandwidth

6 is a conceptual diagram of a new sampling structure according to a combination of sampling points by bandwidth according to an embodiment of the present invention. As shown in FIG. 6, a sampling structure having a new resolution can be determined according to a sampling point combination for bandwidth according to an embodiment of the present invention for quantization error reduction. By using, for example, PRSs each having three different bandwidths (10, 15, 20 MHz) among a plurality of bandwidths set in the 3GPP LTE standard, By obtaining a new sampling point, quantization error due to time-domain sampling can be reduced.

As shown in FIG. 6, PRSs having different bandwidths, such as 10, 15, and 20 MHz bandwidths supported by 3GPP LTE, have different sizes of OFDM subcarrier spaces and FFT sizes You can have a sampling resolution. In relation, for example, the sampling resolution base unit (1Ts) of about 20 MHz bandwidth is about 9.77 m, the sampling resolution base resolution unit of about 15.0 MHz is about 13.02 m, and the base resolution unit of sampling resolution of 10 MHz bandwidth is about 19.53 m do. In this way, the location server can acquire a new structure by increasing the sampling resolution using the relationship between the sampling points that appear differently according to the bandwidth size, using the characteristics of the PRSs having different sampling resolutions according to the bandwidth size . Accordingly, the new structure (see New point) divided by the sampling resolution boundaries of FIG. 6 includes a plurality of sampling points (sampling points 'aaa' to 'daa') representing each of the sampling intervals (interval P1 to P9) ≪ / RTI >

According to the sampling structure according to the embodiment of the present invention, a plurality of PRSs (for example, 20 MHz, 15 MHz, 10 MHz) each having a plurality of bandwidths The reception time of the PRS from the final first base station can be determined based on the sensed sampling points of the PRS.

For example, as shown in FIG. 6, the detected sampling point of the PRS having the bandwidth of 20 MHz received from the first base station is 'a', and the PRS having the bandwidth of 15 MHz received from the first base station If the sensed sampling point is 'a' and the sensed sampling point of the PRS having a bandwidth of 10 MHz received from the first base station is 'a', the sampling resolution boundary indicated by the dashed line indicates the boundary between each sampling interval A sampling interval including the sampling point 'a' having the bandwidth of 20 MHz, a sampling interval including the sampling point 'a' having the bandwidth of 15 MHz, and a sampling interval including the sampling point ' (the same as the interval 'P1' including the sampling point 'aaa' of the New point) of the sampling interval including the sampling points 'a' and 'a' (Sampling point 'aaa') as the reception time of the PRS from the first base station.

Also, for example, if the detected sampling point of the PRS having a bandwidth of 20 MHz received from the first base station is' c 'and the detected sampling point of the PRS having the bandwidth of 15 MHz received from the first base station is' b ', and when the detected sampling point of the PRS having a bandwidth of 10 MHz received from the first base station is' b', when the sampling resolution boundary indicated by the dotted line indicates the boundary between the respective sampling intervals, A sampling interval including a sampling point 'c' having a bandwidth of 15 MHz, a sampling interval including a sampling point 'b' having a bandwidth of 15 MHz and a sampling interval including a sampling point 'b' having a bandwidth of 10 MHz (Sampling point 'cbb') of the common section 'P5' is determined, and a common point of the common section 'P5' (the sampling point 'cbb' The PRS can be determined as the reception time of from the first base station.

Through the same procedure as described above, a new sampling structure according to an embodiment of the present invention can be configured so that a total of nine sampling points from the sampling point 'aaa' to the sampling point 'daa' are repeated. This makes it possible to acquire more sampling points even when compared with the sampling structure of the PRS having the 40 MHz bandwidth having 8 sampling points within the same time interval.

In the above description, PRS having three different bandwidths, for example, 20 MHz, 15 MHz, and 10 MHz, are used. However, for example, PRS having two different bandwidths may be used, or four different A variety of multiple PRSs may be used, such as PRS with bandwidth. Further, if a plurality of different PRSs are used, it is not limited to a specific bandwidth value such as 20 MHz, 15 MHz, 10 MHz.

Variable bandwidth PRS  Transmission-based quantization error Abatement  Way

7 is an information flow diagram of a variable bandwidth PRS transmission-based quantization error reduction method according to an embodiment of the present invention. As described above, the variable bandwidth PRS transmission-based quantization error reduction method according to an exemplary embodiment of the present invention can reduce the quantization error based on a plurality of PRS transmissions having different bandwidth sizes supported in a wireless communication system such as 3GPP LTE, The error can be reduced.

7, a user equipment (UE) 100 requiring location information transmits a location location request signal to an Evolved Serving Mobile Location Center (EBS) 200 through an Evolved NodeB (eNB) -SMLC) 300 (steps 705 and 710). Thereafter, the location server 300 may transmit three PRSs, for example, 10, 15, and 20 MHz, to the terminal 100 through the base station 200 (steps 715 and 720). After the terminal 100 confirms the positions of the sampling points of the received PRS for each bandwidth (step 725), the terminal 100 transmits the RSTD information through the base station 200 using the reporting table defined in the 3GPP LTE standard To the server 300 (steps 730 and 735). The location server 300 performs quantization based on the sampling structure according to an exemplary embodiment of the present invention (step 740), and uses the RSTD information determined by the sampling structure according to an exemplary embodiment of the present invention to perform OTDOA- (Step 745) to determine the location of the terminal 100. The location server 300 may then transmit the location information of the terminal to the terminal 100 through the base station 200 (steps 750 and 755).

FIG. 11 shows an operation of sampling point acquisition and quantization error reduction according to an embodiment of the present invention. As shown in FIG. 11, according to an embodiment of the present invention, a new sampling point may be obtained based on a plurality of PRS transmissions having different bandwidth sizes, thereby reducing a quantization error.

As shown in FIG. 11, the terminal 100 can receive a plurality of PRSs having three different bandwidths transmitted from the first base station 200, and can confirm positions of sampling points measured for respective bandwidths. For example, in the case of receiving the PRS at the PRS receiving point (bold arrow) in FIG. 11, the reception time of the PRS having the bandwidth of 20 MHz is quantized to 'b', and the reception of the PRS having the bandwidth of 15 MHz The time is quantized to 'a', and the reception time of the PRS having a bandwidth of 10 MHz is quantized to 'b', and finally a sampling combination of 'baa' can be obtained. Then, the terminal 100 uses the reporting table defined in the 3GPP LTE standard, for example, based on the reception time ('b', 'a'. 'A') of the PRS from the plurality of first base stations RSTD information between the first base station and the second base station and RSTD information between the first base station and the third base station may be transmitted to the location server 300 for transmission. Based on a new sampling structure according to an embodiment of the present invention, the location server 300 includes a sampling point 'baa' in FIG. 11 including a sampling point of the PRS Quot; baa " representing a period " P2 "

According to another embodiment of the present invention, the terminal 100 calculates the reception time 'b' of the quantized PRS having the bandwidth of 20 MHz, the reception time 'a' of the PRS having the bandwidth of 15 MHz and the bandwidth of 10 MHz Based on the reception time 'a' of the PRS, the PRS reception time from the first base station is quantized to the sampling point 'baa' using the sampling structure according to the embodiment of the present invention, And RSTD between each base station and the first base station among the third base stations and transmit the determined RSTD to the location server 300.

According to embodiments of the present invention, it is possible to obtain more sampling points (9) in comparison with 40 MHz (sampling structure composed of 8 points) within the same time period. Therefore, the variable bandwidth PRS utilizing method according to an embodiment of the present invention can obtain a quantization error reducing effect similar to 40 MHz by utilizing bandwidths of different sizes defined in LTE, without expanding the bandwidth through the CA. Also, there is no need to define a separate reporting table because it does not extend the bandwidth.

A method for measuring the location of a terminal in a wireless communication system -

8 is a flowchart of a method for measuring a position of a UE in a wireless communication system according to an embodiment of the present invention. The method for measuring the position of the terminal shown in FIG. 8 is based on each of the plurality of PRSs having a plurality of bandwidths received from the first base station, as shown in FIG. 7, (RSTD) between the first base station and the second base station and transmits the information to the location server 300 based on the RSTD reporting table defined in the 3GPP LTE standard, the location server 300, < / RTI > in a wireless communication system.

8, according to a method for measuring a position of a terminal in a wireless communication system according to an exemplary embodiment of the present invention, a location server 300 firstly receives a first position determination reference signal having a first bandwidth (PRS) time difference (RSTD) between the first base station and the second base station, which is measured based on the Positioning Reference Signal (PRS) (Step 810). Specifically, for example, the terminal 100 transmits information about the difference between the PRS reception time and the PRS reception time from the second base station, based on the reception time of the PRS having the bandwidth of 20 MHz received from the first base station 200, To the location server 300 in the form of an RSTD reporting table defined in the standard. According to an aspect, the PRS from the second base station may also be a PRS with a bandwidth of 20 MHz.

The location server 300 may then receive information regarding the RSTD between the first and second base stations, measured based on a second PRS having a second bandwidth different from the first bandwidth (step 820). Specifically, for example, the terminal 100 transmits information on the difference between the PRS reception time and the PRS reception time from the second base station, based on the reception time of the PRS having the bandwidth of 15 MHz received from the first base station 200, To the location server 300 in the form of an RSTD reporting table defined in the standard. According to an aspect, the PRS from the second base station may also be a PRS with a bandwidth of 15 MHz.

According to an aspect, the location server 300 further receives information about the RSTD between the first base station and the second base station, measured based on a third PRS having a first bandwidth and a third bandwidth different from the second bandwidth (Step 830). Specifically, for example, the terminal 100 transmits information about the difference between the PRS reception time and the PRS reception time from the second base station, based on the reception time of the PRS having the bandwidth of 10 MHz received from the first base station 200, To the location server 300 in the form of an RSTD reporting table defined in the standard. According to an aspect, the PRS from the second base station may also be a PRS with a bandwidth of 10 MHz. Here, the sampling point interval of the first PRS, the second PRS, and the third PRS may differ according to the size of each bandwidth of the PRSs.

After receiving information on a plurality of RSTDs, the location server 300 transmits information on the RSTD between the first base station and the second base station, which are measured based on the first PRS, and the first base station, Based on the RSTD information between the second base station, the final RSTD between the first base station and the second base station may be determined (step 840) with reference to the sampling structure according to an embodiment of the present invention described above. When information on the RSTD between the first base station and the second base station measured based on the third PRS is further received, information on the RSTD between the first base station and the second base station measured based on the first PRS, Based on the RSTD information measured between the first base station and the second base station measured based on the PRS and the RSTD information measured between the first base station and the second base station based on the third PRS, The final RSTD between the first and second base stations can be determined with reference to the exemplary sampling structure.

9 is a detailed flowchart of the final RSTD determination step of FIG. 9, the step of determining the final RSTD between the first base station and the second base station (step 840) may include detecting a first sampling interval including the detected sampling point of the first PRS and a second sampling interval (Step 841), the final RSTD can be determined (step 843) by considering the midpoint of the common section as the reception time of the PRS from the first base station have.

11, when PRS is received at the PRS reception point (bold arrow) of FIG. 11, the reception time of the PRS having the bandwidth of the first bandwidth (for example, 20 MHz) A reception time of a PRS having a bandwidth of a second bandwidth (for example, 15 MHz) is quantized to 'a', a bandwidth of a third bandwidth (for example, 10 MHz) The reception time of the PRS is quantized to 'b', and the terminal 100 receives the PRS reception time ('b', 'a'. 'A') from the first base station, And transmit the RSTD information between the two base stations to the location server 300 for transmission. Based on a new sampling structure according to an embodiment of the present invention, the location server 300 includes a sampling point 'baa' in FIG. 11 including a sampling point of the PRS Quot; baa " representing the period " P2 ") of the first base station and the second base station, thereby determining the final RSTD between the first base station and the second base station. On the other hand, when the location server 300 analogizes the sampling points of the plurality of PRSs, it is possible to obtain not only the information on the RSTD from the MS but also the RTT (Round Trip Time) received from the BS 200 More information may be used.

Meanwhile, the location server 300 may receive (step 850) information on the RSTD between the first and third base stations from the terminal 100, and may transmit the RSTD information between the first RSTD and the first base station, Based on the information on the RSTD between the third base station, the location of the terminal 100 may be determined (step 860).

10 is a block diagram illustrating a configuration of a location server and a terminal according to another embodiment of the present invention. 10, a location server 300 according to an embodiment of the present invention may include a processor 1050, a memory 1060, and a radio frequency unit (RF) unit 1040. Processor 1050 may implement the proposed functionality, process and / or method, and processor 1050 may also be configured to implement the embodiments of the invention described above with reference to the drawings.

The RF unit 1040 may be functionally coupled to the processor 1050 to transmit and receive wireless signals. The processor 1050 and the RF unit 1040 can be configured to transmit and receive radio signals according to at least one communication standard. The RF unit 1040 may include at least one transceiver capable of transmitting and receiving radio signals.

The processor may comprise an application-specific integrated circuit (ASIC), other chipset, logic circuitry and / or a data processing device. Memory 1060 can include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage devices. The RF unit 1040 may include a baseband circuit for processing a radio signal. When the embodiment is implemented in software, the above-described techniques may be implemented with modules (processes, functions, and so on) that perform the functions described above. The modules may be stored in memory 1060 and executed by processor 1050. [ The memory 1060 may be internal or external to the processor 1050 and may be coupled to the processor 1050 in a variety of well known ways.

Method for measuring the position of a terminal in a wireless communication system -

12 is a flowchart of a method for determining a position of a UE in a wireless communication system according to another embodiment of the present invention. 12 is a diagram illustrating a case where the terminal 100 determines the PRS reception time from the first base station based on each of a plurality of PRSs having a plurality of bandwidths received from the first base station, ≪ / RTI > in a wireless communication system.

12, according to a method for measuring a position of a terminal in a wireless communication system according to an exemplary embodiment of the present invention, a terminal 100 firstly receives a first position measurement having a first bandwidth from a first base station, (PRS) having a first bandwidth and a second PRS having a second bandwidth different from the first bandwidth (step 1210). Specifically, for example, the terminal 100 can receive the PRS having the bandwidth of 20 MHz and the PRS having the bandwidth of 15 MHz from the first base station 200.

According to an aspect, the UE 100 receives a third PRS having a first bandwidth and a third bandwidth different from the second bandwidth from the first base station 200, together with the reception of the first PRS and the second PRS, . Specifically, for example, the terminal 100 can further receive a PRS having a bandwidth of 10 MHz from the first base station 200. [

Subsequently, the terminal 100 may determine the reception time of the PRS from the first base station 100 based on the sensed sampling point of the first PRS and the sensed sampling point of the second PRS (step 1220). When receiving a third PRS having a third bandwidth, the first PRS from the first base station 200, based on the sensed sampling point of the first PRS, the sensed sampling point of the second PRS, and the sensed sampling point of the third PRS, It is possible to determine the reception time of the PRS. Here, the sampling point interval of the first PRS, the second PRS, and the third PRS may differ according to the size of each bandwidth of the PRSs.

13 is a detailed flowchart of the PRS reception time determination step from the first base station in FIG. As shown in FIG. 13, the step of determining the reception time of the PRS from the first base station (step 1220) includes a first sampling interval including the detected sampling point of the first PRS, A common section of the second sampling interval including the sampling point is determined (step 1221), and the center of the common interval is determined as the reception time of the PRS from the first base station (step 1223).

11, when PRS is received at the PRS reception point (bold arrow) of FIG. 11, the reception time of the PRS having the bandwidth of the first bandwidth (for example, 20 MHz) A reception time of a PRS having a bandwidth of a second bandwidth (for example, 15 MHz) is quantized to 'a', a bandwidth of a third bandwidth (for example, 10 MHz) The reception time of the PRS is quantized to be 'b', and the terminal 100 calculates the reception time of the sampling point for each bandwidth based on the reception time ('b', 'a'. 'A') of the PRS from the plurality of first base stations Based on a new sampling structure according to an embodiment of the present invention, which is composed of a plurality of sampling points (sampling points 'baa' in FIG. 11) 'baa', and finally, the quantization of the PRS from the first base station The receiving time can be determined as the sampling point baa.

Meanwhile, the terminal 100 can determine the reception time of the PRS from the second base station and the reception time of the PRS from the third base station (step 1230). According to an aspect of the present invention, in determining the reception time of the PRS from the second base station, a plurality of PRSs each having a plurality of bandwidths are received from the second base station in the same manner as the first base station, The reception time of the PRS from the second base station can be determined.

According to an aspect of the present invention, in determining the reception time of the PRS from the third base station, a plurality of PRSs each having a plurality of bandwidths are received from the third base station, like the first base station, The reception time of the PRS from the third base station can be determined.

When the reception time of each PRS from the first base station, the second base station and the third base station is determined, the terminal 100 calculates a PRS reception time difference (RSTD) between the first base station and the second base station, (Step 1240) between the first base station and the third base station and may transmit the information about the RSTD to the location server 300 (step 1250).

10 is a block diagram illustrating a configuration of a location server and a terminal according to another embodiment of the present invention. 10, a terminal 100 according to an embodiment of the present invention may include a processor 1020, a memory 1030, and a radio frequency unit (RF unit) 1010. The processor 1020 may implement the proposed functions, procedures and / or methods, and the processor 1020 may also be configured to implement the embodiments of the invention described above with reference to the drawings.

The RF unit 1010 may be functionally coupled to the processor 1020 to transmit and receive wireless signals. The processor 1020 and the RF unit 1010 can be configured to transmit and receive radio signals according to at least one communication standard. The RF unit 1010 may include at least one or more transceivers capable of transmitting and receiving radio signals.

The processor may comprise an application-specific integrated circuit (ASIC), other chipset, logic circuitry and / or a data processing device. Memory 1030 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage devices. The RF unit 1010 may include a baseband circuit for processing a radio signal. When the embodiment is implemented in software, the above-described techniques may be implemented with modules (processes, functions, and so on) that perform the functions described above. The module may be stored in memory 1030 and executed by processor 1020. [ The memory 1030 may be internal or external to the processor 1020 and may be coupled to the processor 1020 in a variety of well known means.

Experiment result

The experimental environment for the method for determining the location of the terminal in the wireless communication system according to an embodiment of the present invention is shown in Table 2 below. OTDOA based positioning method was used and the Taylor series algorithm was used to align the hyperbolic equations. The inter-base distance (ISD) is assumed to be 500 m, and the terminal and base station heights are set to 1.5 m and 25 m defined by the 3GPP standard. The FFT size is set to 1024 for 10 MHz, 1536 for 15 MHz, 2048 for 20 MHz, and 4096 for 40 MHz for each bandwidth, and the subcarrier space is all set equal to 15000 Hz.

14 shows CDF performance of the RSTD estimation error between the conventional technique and the technique according to the present invention. Through the computer simulation, the CDD (Cumulative Distribution Function) performance of the RSTD estimation error was analyzed to compare the RSTD error according to the quantization error size by applying the OTDOA based positioning technique of the prior art and the present invention technique. The location location environment is assumed to be LOS (Line Of Sight), and height error and quantization error due to height difference between terminal and base station are applied as positioning deterioration factors.

The RSTD is a difference in reception time of the PRS received from three base stations, and is an important parameter in the OTDOA calculation process for positioning the terminal. Therefore, FIG. 14 is a performance graph comparing the quantization error reduction effect of the technique of the present invention with that of the prior art. As shown in Fig. 14, Conv. 2 graph shows a very good performance due to the RSTD estimation error when the new reporting table is defined considering the accuracy of the ELD algorithm. However, when using the reporting table of 20 MHz which is the maximum bandwidth supported by LTE, No further error reduction effect can be obtained. Dotted and dashed graphs show RSTD estimation errors when using 10, 15, and 20 MHz bandwidths supported by existing LTE systems. The present invention, which utilizes PRSs with different bandwidth sizes defined in LTE, is 6.2 m (10 MHz), 3.2 m (15 MHz), 1.7 m (20 m) at a 67% probability compared to the prior art utilizing a single bandwidth PRS RSTD measurement performance gains of 10.4 m (10 MHz), 5.1 m (15 MHz), and 2.6 m (20 MHz / ELD based fine synchronization) at 95% probability were achieved. On the other hand, measurement accuracy was degraded by 0.2 m at a 67% probability and by 1.2 m at a 95% probability for a 40 MHz bandwidth extension utilizing an intra-band consecutive CA. However, according to the embodiment of the present invention, since the bandwidth through the CA is not extended, there is no need to newly define the RSTD reporting table.

15 shows the CDF performance of the coordinate error RMSE between the conventional technique and the technique according to the present invention. In order to compare the positioning performance according to the quantization error size of the conventional technique and the present invention technique through a computer simulation, a CDF (Cumulative Distribution Function) performance of a two-dimensional coordinate error RMSE was analyzed. As shown in Fig. 15, Conv. 2 is an ideal case in which the reporting table is newly defined in consideration of the accuracy of the ELD algorithm, but it can be confirmed that the positioning performance is somewhat deteriorated due to the height error between the terminal and the base station.

As shown in FIG. 15, the quantization error reduction method according to an embodiment of the present invention compared to the prior art of PRS and ELD based algorithms of a single bandwidth (10, 15, and 20 MHz) has excellent positioning performance. According to an embodiment of the present invention, the positioning performance of 5.7 m (10 MHz), 3.0 m (15 MHz), and 1.7 m (20 MHz / ELD based fine synchronization) at a probability of 67% , Achieving performance gains of 7.8 m (10 MHz), 4.1 m (15 MHz) and 2.0 m (20 MHz / ELD based fine synchronization) at 95% probability. However, according to the embodiment of the present invention, it is confirmed that the positioning performance is slightly deteriorated by 0.4 m at the probability of 67% and by 1.2 m at the probability of 95%, compared with the case of using the 40 MHz bandwidth extension method through the CA. 11, in a new sampling structure consisting of a combination of sampling points at different positions according to the bandwidth size in one embodiment of the present invention, a specific sampling period such as 'aaa' is sampled at 40 MHz bandwidth The quantization error is relatively large at the time of receiving the PRS in the corresponding section, and the positioning performance may be deteriorated. However, the quantization error reduction method according to an embodiment of the present invention utilizes PRS having different bandwidth sizes supported by LTE, thereby achieving positioning performance similar to 40 MHz without bandwidth expansion or reconfiguration of the RSTD reporting table Respectively.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill 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 by the following claims. It will be understood.

100: terminal
200: base station
300: Location server

Claims (24)

A method for measuring a position of a terminal in a wireless communication system, the method being performed by a location server,
(PRS) reception time difference (RSTD) between the first base station and the second base station, which is measured based on a first positioning reference signal (PRS) having a first bandwidth step;
Receiving information about the RSTD between the first base station and the second base station based on a second PRS having a second bandwidth different from the first bandwidth; And
Based on the information about the RSTD between the first base station and the second base station measured based on the first PRS and the information about the RSTD between the first base station and the second base station measured based on the second PRS, And determining a final RSTD between one base station and the second base station. The method according to claim 1,
Wherein a sampling point interval of the first PRS and the second PRS is different according to each bandwidth size of the first PRS and the second PRS. The method according to claim 1,
Wherein determining the final RSTD between the first and second base stations comprises:
Determining a common interval between a first sampling interval including a sensed sampling point of the first PRS and a second sampling interval including a sensed sampling point of the second PRS; And
And determining the final RSTD by considering the midpoint of the common interval as the reception time of the PRS from the first base station. The method according to claim 1,
Receiving information on RSTD between a first base station and a third base station; And
Determining a location of the terminal based on information on the last RSTD between the first and second base stations and the RSTD between the first and third base stations, . The method according to claim 1,
The method is performed by an Evolved Serving Mobile Location Center (E-SMLC). The method according to claim 1,
Further comprising receiving information about the RSTD between the first base station and the second base station, measured based on a third PRS having a first bandwidth and a third bandwidth different from the second bandwidth,
Wherein the determining the final RSTD comprises: determining information about the RSTD between the first base station and the second base station based on the first PRS, determining information on the RSTD between the first base station and the second base station based on the second PRS, Determining the final RSTD based on information about the RSTD and information on the RSTD between the first base station and the second base station measured based on the third PRS. A location server operating in a wireless communication system,
The location server comprises:
A radio frequency (RF) unit for transmitting and receiving a radio signal; And
And a processor operatively coupled to the RF unit,
The processor comprising:
(PRS) reception time difference (RSTD) between the first base station and the second base station, which is measured based on a first positioning reference signal (PRS) having a first bandwidth that;
Receiving information about the RSTD between the first base station and the second base station, measured based on a second PRS having a second bandwidth different from the first bandwidth; And
Based on the information about the RSTD between the first base station and the second base station measured based on the first PRS and the information about the RSTD between the first base station and the second base station measured based on the second PRS, And to determine a final RSTD between one base station and the second base station. 8. The method of claim 7,
Wherein a sampling point interval of the first PRS and the second PRS is different according to each bandwidth size of the first PRS and the second PRS. 8. The method of claim 7,
Determining a final RSTD between the first and second base stations,
Determining a common interval between a first sampling interval including a sensed sampling point of the first PRS and a second sampling interval including a sensed sampling point of the second PRS; And
And determining the final RSTD by considering the midpoint of the common interval as the reception time of the PRS from the first base station. 8. The method of claim 7,
The processor comprising:
Receiving information about the RSTD between the first base station and the third base station; And
Wherein the location server is further configured to determine a location of the terminal based on information regarding the last RSTD between the first and second base stations and the RSTD between the first and third base stations. 8. The method of claim 7,
Wherein the location server is an Evolved Serving Mobile Location Center (E-SMLC). 8. The method of claim 7,
The processor comprising:
Further comprising receiving information about the RSTD between the first and second base stations, measured based on a third PRS having a first bandwidth and a third bandwidth different from the second bandwidth,
The determination of the final RSTD may include determining RSTD between the first base station and the second base station based on the first PRS, determining RSTD between the first base station and the second base station based on the second PRS, And determines the final RSTD based on information on the RSTD between the first base station and the second base station measured based on the third PRS. CLAIMS What is claimed is: 1. A method for measuring a position of a terminal in a wireless communication system,
Receiving a first Positioning Reference Signal (PRS) having a first bandwidth from a first base station and a second PRS having a second bandwidth different from the first bandwidth; And
Determining a reception time of the PRS from the first base station based on the sensed sampling point of the first PRS and the sensed sampling point of the second PRS. 14. The method of claim 13,
Wherein a sampling point interval of the first PRS and the second PRS is different according to each bandwidth size of the first PRS and the second PRS. 14. The method of claim 13,
Wherein the step of determining the reception time of the PRS from the first base station comprises:
Determining a common interval between a first sampling interval including a sensed sampling point of the first PRS and a second sampling interval including a sensed sampling point of the second PRS; And
And determining a center point of the common section as the reception time of the PRS from the first base station. 14. The method of claim 13,
Determining a reception time of the PRS from the second base station and a reception time of the PRS from the third base station;
Determining a PRS reception time difference (RSTD) between the first base station and the second base station and an RSTD between the first base station and the third base station; And
Further comprising transmitting information about the RSTD to a location server. 17. The method of claim 16,
Wherein the location server is an Evolved Serving Mobile Location Center (E-SMLC). 14. The method of claim 13,
Wherein the receiving the first PRS and the second PRS further comprises receiving a third PRS from the first base station having a third bandwidth different from the first bandwidth and the second bandwidth,
Wherein the step of determining the reception time of the PRS from the first base station comprises the step of determining the reception time of the PRS based on the sensed sampling point of the first PRS, the sensed sampling point of the second PRS, A method for measuring a position of a terminal, the method comprising: determining a reception time of a PRS from one base station; 1. A terminal operating in a wireless communication system,
The terminal,
A radio frequency (RF) unit for transmitting and receiving a radio signal; And
And a processor operatively coupled to the RF unit,
The processor comprising:
Receiving a first Positioning Reference Signal (PRS) having a first bandwidth from a first base station and a second PRS having a second bandwidth different from the first bandwidth; And
And to determine a reception time of the PRS from the first base station based on the sensed sampling point of the first PRS and the sensed sampling point of the second PRS. 20. The method of claim 19,
Wherein a sampling point interval of the first PRS and the second PRS is different according to a bandwidth size of each of the first PRS and the second PRS. 20. The method of claim 19,
Determining the reception time of the PRS from the first base station,
Determining a common interval between a first sampling interval including a sensed sampling point of the first PRS and a second sampling interval including a sensed sampling point of the second PRS; And
And determining a center point of the common section as the reception time of the PRS from the first base station. 20. The method of claim 19,
The processor comprising:
Determining a reception time of the PRS from the second base station and a reception time of the PRS from the third base station;
Determining a PRS reception time difference (RSTD) between the first base station and the second base station and an RSTD between the first base station and the third base station; And
Further comprising transmitting information regarding the RSTD to a location server. 23. The method of claim 22,
Wherein the location server is an Evolved Serving Mobile Location Center (E-SMLC). 20. The method of claim 19,
Receiving the first PRS and the second PRS further comprises receiving from the first base station a third PRS having a third bandwidth different from the first bandwidth and the second bandwidth,
Wherein determining the reception time of the PRS from the first base station is based on a sensed sampling point of the first PRS, a sensed sampling point of the second PRS, and a sensed sampling point of the third PRS, And determines the reception time of the PRS from the terminal.

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