Method for searching for enhanced physical downlink control channel region

• US 9,419,763 B2
• Filed: 05/31/2012
• Issued: 08/16/2016
• Est. Priority Date: 05/31/2011
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Jang, Jiwoong, Chung, Jaehoon
• Primary Examiner(s): Marcelo, Melvin
• Assistant Examiner(s): Solinsky, Peter
• Application Number:
  US14/123,173
• Publication Number:
  US 20140105156A1
• Time in Patent Office: 1,538 Days
• Field of Search: 370/329
• US Class Current: 1/1
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0046 Code rate detection or code type detection H04L1/0038 takes precedence; detection of the data rate H04L25/0262; for packet format H04L1/0091
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals

Abstract

The present invention relates to methods for searching an enhanced physical downlink control channel (E-PDCCH), and a device for supporting the methods. According to one embodiment of the present invention, a method for searching an enhanced physical downlink control channel (E-PDCCH) in a wireless access system can comprise the steps of: performing a blind decoding on a control channel region and searching a legacy physical downlink control channel (PDCCH); and searching the E-PDCCH on the basis of the searched legacy PDCCH. In this case, in a subframe to which the E-PDCCH is allocated, using all symbols of the subframe from a first symbol to a third symbol is always preferred for allocation of the legacy PDCCH.

Claims

1. A method for searching for an Enhanced Physical Downlink Control Channel (E-PDCCH) in a wireless access system, the method comprising;

searching for a legacy Physical Downlink Control Channel (PDCCH) by blind-decoding a control channel region; and

searching for the E-PDCCH based on the detected legacy PDCCH,

wherein a position of the E-PDCCH is determined as a function of a position of the legacy PDCCH and the E-PDCCH is searched based on the position of the legacy PDCCH without an additional search operation,

wherein if the legacy PDCCH and E-PDCCH are allocated in a subframe, the legacy PDCCH always occupies all of first, second, and third symbols of the subframe,

and

wherein the position of the legacy E-PDCCH is defined by a starting position of the legacy PDCCH, an ending position of the legacy PDCCH and a size of the legacy PDCCH.

2. The method according to claim 1, wherein a legacy PDCCH signal transmitted on the legacy PDCCH is masked with User Equipment (UE)-specific Cyclic Redundancy Check (CRC).

3. The method according to claim 2, wherein an E-PDCCH signal transmitted on the E-PDCCH is masked with a common CRC.

4. The method according to claim 2, wherein an E-PDCCH signal transmitted on the E-PDCCH is masked with the UE-specific CRC.

5. The method according to claim 1, further comprising acquiring information about an allocated position of the E-PDCCH using information about at least one of a starting position, an ending position, and a size of a region to which the legacy PDCCH is allocated,

wherein the searching for the E-PDCCH comprises searching for the E-PDCCH based on the information about the allocated position of the E-PDCCH and the E-PDCCH is allocated to a data channel region other than the control channel region.

6. The method according to claim 5, wherein the information about the allocated position of the E-PDCCH, is calculated by a function where is information about a starting position of the legacy PDCCH, is information about an ending position of the legacy PDCCH, and is information about a size of the legacy PDCCH.

7. The method according to claim 1, the function is defined by the relation between a position and a size of the legacy PDCCH and a position and a size of the E-PDCCH.

8. The method according to claim 1, the function is defined as the below equation,

l_enh=f(l_leg^start,l_leg^end,s_leg),

wherein the l_enh represents the E-PDCCH, l_leg^start represents the starting position of the legacy PDCCH, l_leg^end represents the ending position of the legacy PDCCH and s_leg represents the size of the legacy PDCCH.

9. A User Equipment (UE) for searching for an Enhanced Physical Downlink Control Channel (E-PDCCH) in a wireless access system, the UE comprising;

a transmission module;

a reception module; and

a processor configured to control the transmission module and reception module,

wherein the processor is further configured to;

search for a legacy Physical Downlink Control Channel (PDCCH) by blind-decoding a control channel region, and

search for the E-PDCCH based on the detected legacy PDCCH,

wherein a position of the E-PDCCH is determined as a function of a position of the legacy PDCCH and the E-PDCCH is searched based on the position of the legacy PDCCH without an additional search operation,

wherein if the legacy PDCCH and E-PDCCH are allocated in a subframe, the legacy PDCCH always occupies all of first, second, and third symbols of the subframe,

and

wherein the position of the legacy E-PDCCH is defined by a starting position of the legacy PDCCH, an ending position of the legacy PDCCH and a size of the legacy PDCCH.

10. The UE according to claim 9, wherein a legacy PDCCH signal transmitted on the legacy PDCCH is masked with UE-specific Cyclic Redundancy Check (CRC).

11. The UE according to claim 10, wherein an E-PDCCH signal transmitted on the E-PDCCH is masked with a common CRC.

12. The UE according to claim 10, wherein an E-PDCCH signal transmitted on the E-PDCCH is masked with the UE-specific CRC.

13. The UE according to claim 9, wherein the processor acquires information about an allocated position of the E-PDCCH using information about at least one of a starting position, an ending position, and a size of a region to which the legacy PDCCH is allocated,

wherein the processor searches for the E-PDCCH based on the information about the allocated position of the E-PDCCH and the E-PDCCH is allocated to a data channel region other than the control channel region.

14. The UE according to claim 13, wherein the information about the allocated position of the E-PDCCH, is calculated by a function where is information about a starting position of the legacy PDCCH, is information about an ending position of the legacy PDCCH, and is information about a size of the legacy PDCCH.