# US 11,122,537 B2 · Method for estimating distance between D2D terminals and apparatus for method in wireless communication system

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- Number: US 11,122,537 B2
- Document ID: US11122537B2
- Status: Granted
- Kind: B2
- Application number: 16/095,819
- Filed: 2016-12-20
- Published: 2021-07-22
- Granted: 2021-09-14
- Earliest claimed: 2016-04-25
- Assignees: LG Electronics Inc.
- Applicants: LG Electronics Inc.
- Inventors: Seokmin Shin; Hanbyul Seo
- Web page: https://patentgrep.com/patent/US11122537B2

## CPC

- G01S 5/0284: {Relative positioning}
- G01S 5/0072: {Transmission between mobile stations, e.g. anti-collision systems}
- G01S 5/0249: {Determining position using measurements made by a non-stationary device other than the device whose position is being determined}
- H04W 4/023: {using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds}
- H04W 4/70: Services for machine-to-machine communication [M2M] or machine type communication [MTC]
- H04W 8/005: {Discovery of network devices, e.g. terminals}
- H04W 24/08: Testing, {supervising or monitoring} using real traffic
- H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports}
- H04W 64/00: Locating users or terminals {or network equipment} for network management purposes, e.g. mobility management
- H04W 64/006: {with additional information processing, e.g. for direction or speed determination}
- H04W 74/0833: Random access procedures, e.g. with 4-step access
- G01S 5/10: Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements {, e.g. omega or decca systems}(G01S5/12 takes precedence {; beacons and receivers cooperating therewith G01S1/306, G01S1/308})
- G01S 5/14: Determining absolute distances from a plurality of spaced points of known location
- H04W 74/0838: using contention-free random access [CFRA]
- H04W 92/18: between terminal devices
- G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

A method for estimating the distance between device-to-device (D2D) terminals in a wireless communication system according to the present specification, carried out by a first D2D terminal, is characterized by comprising the steps of: receiving, from a second D2D terminal, a particular message comprising first distance information, regarding the differences in distance between the second D2D terminal and at least three reference base stations configured thereby, and second distance information indicating the distances between said at least three reference base stations; measuring the distance to each reference base station; and estimating the distance to the second D2D terminal by means of the measured distance to each reference base station, first distance information and second distance information.

## Claims

### Claim 1

A method of estimating a distance between device-to-device (D2D) user equipments (UEs) in a wireless communication system, the method performed by a first D2D UE comprising:
receiving, from a second D2D UE, a specific message comprising first distance information related to a distance difference between the second D2D UE and at least three reference eNBs configured by the second D2D UE and second distance information indicating a distance between the at least three reference eNBs;
measuring a distance between the reference eNBs; and
estimating a distance from the second D2D UE using the measured distances between the reference eNBs, the first distance information and the second distance information.

### Claim 2 (depends on 1)

The method of claim 1, wherein the first distance information is determined based on reference signals (RS) transmitted by the respective reference eNBs.

### Claim 3 (depends on 2)

The method of claim 2, wherein the reference signal comprises a positioning reference signal (PRS).

### Claim 4 (depends on 2)

The method of claim 2, wherein the first distance information comprises a reference signal time difference (RSTD) indicating a difference between times of the reference signals transmitted by the respective reference eNBs.

### Claim 5 (depends on 1)

The method of claim 1, wherein:
the first D2D UE indicates an operation UE which is a subject of distance estimation between the D2D UEs, and
the second D2D UE is a target UE which is a subject of distance estimation between the D2D UEs.

### Claim 6 (depends on 1)

The method of claim 1, wherein estimating the distance from the second D2D UE comprises:
determining a candidate point where the second D2D UE is able to be positioned based on the second distance information; and
determining a position of the second D2D UE using the first distance information at the determined candidate point.

### Claim 7 (depends on 6)

The method of claim 6, wherein determining the candidate point comprises forming a circle using a distance between the reference eNBs as a radius and a position of each reference eNB as a center.

### Claim 8 (depends on 7)

The method of claim 7, wherein:
determining the position of the second D2D UE comprises forming at least three hyperbolas based on positions of two reference eNBs using the first distance information, and
a point where the formed at least three hyperbolas are met in common among the candidate points is determined as the position of the second D2D UE.

### Claim 9 (depends on 8)

The method of claim 8, wherein the measured distance between the reference eNBs is measured using timing advance (TA) obtained through a random access procedure with each reference eNB or is measured using a positioning reference signal transmitted by each of the reference eNBs.

### Claim 10 (depends on 9)

The method of claim 9, wherein at least one of transmission periodicity, a coding rate and transmit power is differently set in each of the first distance information and second distance information, received from the second D2D UE, depending on the distance from the second D2D UE.

### Claim 11 (depends on 1)

The method of claim 1, wherein the specific message comprises a D2D discovery signal or D2D data.

### Claim 12

A first device-to-device (D2D) user equipment (UE) for estimating a distance between D2D UEs in a wireless communication system, the D2D UE comprising:
a radio frequency (RF) unit for transmitting and receiving radio signals; and
a processor functionally connected to the RF unit, wherein the processor is configured to control to:
receive, from a second D2D UE, a specific message comprising first distance information related to a distance difference between the second D2D UE and at least three reference eNBs configured by the second D2D UE and second distance information indicating a distance between the at least three reference eNBs;
measure a distance between the reference eNBs; and
estimate a distance from the second D2D UE using the measured distances between the reference eNBs, the first distance information and the second distance information.