Method and apparatus for performing handover in wireless communication system

Patent metadata

Field	Value
Publication number	US-9578558-B2
Application number	US-201314420895-A
Country	US
Kind code	B2
Filing date	Aug 14, 2013
Priority date	Aug 15, 2012
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

The present invention relates to a method for a terminal to perform a handover in a wireless communication system, including the steps of: receiving a handover instruction from a serving cell; and performing a random access procedure for a target cell according to the handover instruction, wherein, when interference adjustment is performed on the serving cell and the target cell, system information for the target cell is obtained from the serving cell.

First claim

What is claimed is:

1. A method of performing a handover, by a user equipment, in a wireless communication system, comprising:
receiving a handover command from a serving cell;
wherein the serving cell and a target cell perform inter-cell interference coordination, and
wherein system information of the target cell is received from the serving cell with the handover command,
obtaining synchronization of the target cell, and
performing a random access procedure for the target cell according to the handover command;
wherein the system information includes a subframe offset when a time boundary is matched with each other between the serving cell and the target cell, and
wherein the synchronization of the target cell is obtained based on a subframe number of the serving cell and the subframe offset.

2. The method of claim 1 , wherein the target cell corresponds to a victim cell interfered by the serving cell.

3. The method of claim 1 , wherein the user equipment assumes that system information not contained in the system information received with the handover command is identical to system information of the serving cell.

4. The method of claim 1 , wherein the user equipment considers system information of the serving cell as the system information of the target cell.

5. The method of claim 1 , wherein the system information is transmitted on a physical broadcast channel in the serving cell.

6. The method of claim 1 , wherein the user equipment is located in a CRE (cell range extension) region of the target cell.

7. The method of claim 1 , wherein the handover command is contained in an Radio Resource Control (RRC) connection reconfiguration information element.

8. The method of claim 1 , wherein the user equipment recognizes that the inter-cell interference coordination is performed using signaling indicating that the target cell corresponds to a victim cell.

9. The method of claim 1 , wherein the user equipment recognizes that the inter-cell interference coordination is performed when a signal related to one selected from the group consisting of a subframe set for restricted measurement, ABS (almost blank subframe) configuration and adjustment of a threshold associated with a criterion of a measurement report is received.

10. The method of claim 1 , wherein the user equipment omits decoding on a physical broadcast channel transmitted from the target cell.

11. A user equipment in a wireless communication system, comprising:
a reception module; and
a processor,
wherein the processor configured to:
receive a handover command from a serving cell,
wherein the serving cell and a target cell perform inter-cell interference coordination, and
wherein system information of the target cell is received from the serving cell with the handover command,
obtain synchronization of the target cell, and
perform a random access procedure for the target cell according to the handover command,
wherein the system information includes a subframe offset when a time boundary is matched with each other between the serving cell and the target cell, and
wherein the synchronization of the target cell is obtained based on a subframe number of the serving cell and the subframe offset.

Assignees

• Lg Electronics Inc

Inventors

• Seo Inkwon
• Seo Hanbyul
• Kim Eunsun

Classifications

• H04L1/0026

  Transmission of channel quality indication · CPC title

• H04L1/00

  Arrangements for detecting or preventing errors in the information received {(correcting synchronisation H04L7/00)} · CPC title

• H04W74/08

  Non-scheduled access, e.g. ALOHA (hybrid access H04W74/02) · CPC title

• H04W36/20

  for optimising the interference level · CPC title

• H04W74/0833

  Random access procedures, e.g. with 4-step access · CPC title