METHOD AND APPARATUS FOR MAKING HARQS IN CARRIER AGGREGATION SYSTEMS

• US 20150085782A1
• Filed: 04/23/2013
• Published: 03/26/2015
• Est. Priority Date: 04/23/2012
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Seo, Dongyoun, Kim, Bonghoe, Ahn, Joonkui, Yang, Suckchel, Seo, Hanbyul, Lee, Seungmin, Yi, Yunjung
• Granted Patent: US 9,602,253 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 1/1822 involving configuration of automatic repeat request [ARQ] with parallel processes
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/1861 Physical mapping arrangements for ACK signaling see also H04L5/0053
• CPC Class Codes: H04L 1/1896 ARQ related signaling
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

The present invention relates to a method and system for making a hybrid automatic repeat requests (HARQ) in a carrier aggregation system. The method receives downlink data through a first subframe of a first carrier, transmits acknowledgement/negative-acknowledgement (ACK/NACK) for the downlink data through a second subframe of a second carrier, and re-receives the downlink data through a third subframe of the first carrier, wherein the first carrier only includes the downlink subframes, and the second carrier includes the uplink subframes and the downlink subframes.

Claims

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

receiving downlink data through a first subframe of a first carrier;

transmitting acknowledgement/not-acknowledgement (ACK/NACK) for the downlink data through a second subframe of a second carrier; and

receiving the downlink data again through a third subframe of the first carrier,

wherein the first carrier is a carrier which s comprised of downlink subframe only, and wherein the second carrier includes the uplink subframe and the downlink subframe.

2. The method of claim 1, wherein a number of maximum HARQ process of the first carrier is determined as the number of the downlink subframe of the first carrier which is included in an interval that corresponds to sum of time difference between the second subframe and the first subframe and the time difference between the third subframe and the second subframe.

3. The method of claim 2, wherein a number of maximum HARQ process of the first carrier is configured as the same as a number of maximum HARQ process of the second carrier.

4. The method of claim 1, wherein a number of maximum HARQ process of the first carrier is determined as the number of the downlink subframe of the first carrier which is included in an interval that corresponds to a time difference between the subframe to which the downlink data that becomes an object of ACK/NACK of the second subframe is transmitted in the second carrier and the subframe to which the downlink data is retransmitted in the second carrier.

5. The method of claim 1, wherein a number of maximum HARQ process of the first carrier is fixed to 8.

6. The method of claim 1, further comprising:

receiving an uplink-downlink (UL-DL) configuration for each of the first carrier and the second carrier,

wherein the UL-DL configuration indicates whether each of the subframes included in a frame is the downlink subframe or the uplink subframe.

7. The method of claim 6, wherein the UL-DL configuration is configured that all subframes in a frame indicates the downlink subframe.

8. The method of claim 1, wherein a downlink grant that schedule the downlink data is received from the first subframe.

9. The method of claim 1, wherein a downlink grant that schedule the downlink data is received from the second subframe.

10. The method of claim 1, wherein the second carrier is included in a primary cell that performs initial connection establishment process or connection reestablishment process with a base station.

11. The method of claim 10, wherein the first carrier is a secondary cell which is added to the primary cell.

12. An apparatus for performing hybrid automatic repeat request (HARQ) in a carrier aggregation system, the apparatus comprising:

a radio frequency (RF) unit that transmits and receives a radio signal; and

a processor connected with the RF unit,

wherein the process is configured to perform,

receiving downlink data through a first subframe of a first carrier;

transmitting acknowledgement/not-acknowledgement (ACK/NACK) for the downlink data through a second subframe of a second carrier; and

receiving the downlink data again through a third subframe of the first carrier,

wherein the first carrier is a carrier which s comprised of downlink subframe only, and wherein the second carrier includes the uplink subframe and the downlink subframe.