METHOD AND DEVICE FOR A HYBRID AUTOMATIC REPEAT REQUEST IN A MULTI-CARRIER SYSTEM

• US 20120327783A1
• Filed: 01/12/2011
• Published: 12/27/2012
• Est. Priority Date: 01/21/2010
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Moon, Sung Ho, Chung, Jae Hoon, Han, Seung Hee, Kim, So Yeon
• Granted Patent: US 9,166,747 B2
• Time in Patent Office: Days
• US Class Current: 370/241
• CPC Class Codes: H04L 1/1861 Physical mapping arrangements for ACK signaling see also H04L5/0053
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated

Abstract

A method of performing hybrid automatic repeat request (HARQ) in a carrier aggregation system is provided. The method includes: monitoring a downlink (DL) grant for initial DL data transmission in a first DL component carrier (CC); receiving initial DL data through a second DL CC indicated by the DL grant; decoding the initial DL data; transmitting a not-acknowledgment (NACK) signal when decoding of the initial DL data fails; monitoring a DL grant for retransmission of the DL data in the first DL CC; and receiving DL data retransmitted through the second DL CC, wherein the second DL CC is any one of a plurality of DL CCs having a predetermined link relation with the first DL CC, and the DL grant for the initial transmission includes a carrier indication field indicating the second DL CC and resource allocation information for the initially transmitted DL data.

Claims

1. A method of performing hybrid automatic repeat request (HARQ) in a carrier aggregation system, the method comprising:

monitoring a downlink (DL) grant for initial DL data transmission in a first DL component carrier (CC);

receiving initial DL data through a second DL CC indicated by the DL grant;

decoding the initial DL data;

transmitting a not-acknowledgment (NACK) signal when decoding of the initial DL data fails;

monitoring a DL grant for retransmission of the DL data in the first DL CC; and

receiving DL data retransmitted through the second DL CC,

wherein the second DL CC is any one of a plurality of DL CCs having a predetermined link relation with the first DL CC, and the DL grant for the initial transmission includes a carrier indication field indicating the second DL CC and resource allocation information for the initially transmitted DL data.

2. The method of claim 1, wherein the DL grant for retransmission includes other fields than the carrier indication field.

3. The method of claim 1,

wherein the DL grant for retransmission consists of the same bit size as the DL grant for initial transmission, and

wherein the carrier indication field included in the DL grant for retransmission is used for other usages than indicating the second DL CC.

4. The method of claim 3, wherein the carrier indication field is used for error detection of the resource allocation information for the retransmitted DL data.

5. The method of claim 1, wherein the first DL CC is any one of a plurality of DL CCs configured through a higher layer signal.

6. The method of claim 1, wherein the DL grant for initial transmission and the DL grant for retransmission are transmitted through a physical downlink control channel (PDCCH).

7. The method of claim 1, wherein the carrier indication field consists of 3 bits.

8. The method of claim 1, wherein the NACK signal is transmitted four subframes later from a subframe in which the initial DL data is received.

9. The method of claim 8, wherein a subframe in which the retransmitted DL data is received is a subframe located 8 subframes later from the subframe in which the initial DL data is received.

10. The method of claim 1, wherein the first DL CC and the second DL CC are component carriers having the same bandwidth and different center frequencies.

11. A user equipment comprising:

a radio frequency (RF) unit for transmitting and receiving a radio signal; and

a processor coupled to the RF unit, wherein the processor is configured for;

monitoring a DL grant for initial DL data transmission in a first DL CC;

receiving initial DL data through a second DL CC indicated by the DL grant;

decoding the initial DL data;

transmitting a NACK signal when decoding of the initial DL data fails;

monitoring a DL grant for retransmission of the DL data in the first DL CC; and

receiving DL data retransmitted through the second DL CC,

wherein the second DL CC is any one of a plurality of DL CCs having a predetermined link relation with the first DL CC, and the DL grant for the initial transmission includes a carrier indication field indicating the second DL CC and resource allocation information for the initially transmitted DL data.

12. The user equipment of claim 11, wherein the DL grant for retransmission includes other fields than the carrier indication field.

13. The user equipment of claim 11,

wherein the DL grant for retransmission consists of the same bit size as the DL grant for initial transmission, and

wherein the carrier indication field included in the DL grant for retransmission is used for other usages than indicating the second DL CC.