# US 10,321,500 B2 · Method and apparatus for transmitting/receiving signal by device-to-device UE in wireless communication system

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,321,500 B2
- Document ID: US10321500B2
- Status: Granted
- Kind: B2
- Application number: 15/311,792
- Filed: 2015-05-18
- Published: 2017-04-06
- Granted: 2019-06-11
- Earliest claimed: 2014-05-18
- Assignees: LG Electronics Inc.
- Applicants: LG Electronics Inc.
- Inventors: Hyukjin Chae; Hanbyul Seo
- Web page: https://patentgrep.com/patent/US10321500B2

## CPC

- H04W 76/14: Direct-mode setup
- H04L 1/0041: {Arrangements at the transmitter end}
- H04L 1/0045: {Arrangements at the receiver end}
- H04L 1/0061: {Error detection codes}
- H04L 27/2602: {Signal structure}
- H04L 27/2607: {Cyclic extensions}
- H04W 8/005: {Discovery of network devices, e.g. terminals}
- H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)}
- H04W 84/042: {Public Land Mobile systems, e.g. cellular systems}
- H04W 88/04: adapted for relaying to or from another terminal or user
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

An embodiment of the present invention relates to a method for transmitting/receiving a signal by a device-to-device (D2D) UE in a wireless communication system, the method comprising the steps of: receiving a discovery signal; and checking a CRC of the discovery signal wherein when at least a part of the CRC is masked by a preconfigured sequence, the UE acquires, from the discovery signal, backhaul link quality information of an apparatus which has transmitted the discovery signal.

## Claims

### Claim 1

A method of transmitting and receiving signals, which are transmitted and received by a device-to-device (D2D) user equipment (UE) in a wireless communication system, the method comprising:
receiving a discovery signal;
checking a Cyclic Redundancy Check (CRC) of the discovery signal,
wherein the CRC of the discovery signal includes first bits masked with a synchronization source ID and second bits masked with a predetermined sequence;
identifying whether the UE that transmitted the discovery signal is a relay UE or a non-relay UE based on the predetermined sequence masked in the second bits; and
obtaining a backhaul link quality information from the discovery signal when the predetermined sequence is a sequence relating to the relay UE.

### Claim 2 (depends on 1)

The method of claim 1, wherein the UE uses the backhaul link quality information in selecting the relay UE from a plurality of relay UEs.

### Claim 3 (depends on 1)

The method of claim 1, wherein a configuration of a discovery signal is different according to the predetermined sequence masked in the second bits.

### Claim 4 (depends on 1)

The method of claim 1, wherein a length of information bits of the discovery signal is not related to the predetermined sequence used in masking the second bits of the CRC.

### Claim 5

A device-to-device (D2D) user equipment (UE) in a wireless communication system, comprising:
a a receiver; and
a processor,
wherein the processor receives a discovery signal and check a Cyclic Redundancy Check (CRC) of the discovery signal,
wherein the CRC of the discovery signal includes first bits masked with a synchronization source ID and second bits masked with a predetermined sequence,
wherein the processor identifies whether the UE that transmitted the discovery signal is a relay UE or a non-relay UE based on the predetermined sequence masked in the second bits, and
wherein the processor obtains a backhaul link quality information from the discovery signal when the predetermined sequence is a sequence relating to the relay UE.

### Claim 6 (depends on 5)

The UE of claim 5, wherein the backhaul link quality information is used in selecting the relay UE from a plurality of relay UEs.

### Claim 7 (depends on 5)

The UE of claim 5, wherein a configuration of a discovery signal is different according to the predetermined sequence masked in the second bits.

### Claim 8 (depends on 5)

The UE of claim 5, wherein a length of information bits of the discovery signal is not related to the predetermined sequence used in masking the second bits of the CRC.