METHOD AND APPARATUS FOR CONTROLLING SOFT BUFFER FOR TDD-FDD CARRIER AGGREGATION

• US 20150181590A1
• Filed: 12/24/2014
• Published: 06/25/2015
• Est. Priority Date: 12/24/2013
• Status: Active Grant

• Current Assignee: InnoSky, Co., SK Telecom Co., Ltd.
• Original Assignee: Innovative Tech Lab Company Limited
• Inventors: PARK, Dong Hyun
• Granted Patent: US 10,128,986 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1822 involving configuration of automatic repeat request [ARQ] with parallel processes
• 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 5/1469 using time-sharing

Abstract

Provided is a method and apparatus for controlling soft buffer for TDD-FDD carrier aggregation. The method includes: establishing a Radio Resource Control (RRC) connection with a base station through a first serving cell, the first serving cell supporting a Time Division Duplex (TDD) mode; receiving an RRC message from the base station through the first serving cell, the RRC message comprising carrier aggregation (CA) configuration information, the CA configuration information comprising information of a second serving cell supporting a Frequency Division Duplex (FDD) mode; determining a maximum number of DL HARQ processes for the second serving cell, the maximum number of DL HARQ processes for the second serving cell being differently determined according to a DL reference timing; and storing soft channel bits for a received transport block (TB) based on the determined maximum number of DL HARQ processes for the second serving cell.

Claims

1. A method of performing a Hybrid Automatic Repeat reQuest (HARQ) operation by a user equipment (UE), the method comprising:

establishing a Radio Resource Control (RRC) connection with a base station through a first serving cell, the first serving cell supporting a Time Division Duplex (TDD) mode, and a TDD uplink(UL)-downlink(DL) configuration of the first serving cell being one of 1, 2, 3, 4, and 5;

receiving an RRC message from the base station through the first serving cell, the RRC message comprising carrier aggregation (CA) configuration information, the CA configuration information comprising information of a second serving cell supporting a Frequency Division Duplex (FDD) mode, and the first serving cell and the second serving cell being aggregated by a TDD-FDD CA scheme;

determining a maximum number of DL HARQ processes for the second serving cell, the maximum number of DL HARQ processes for the second serving cell being differently determined according to a DL reference timing; and

storing soft channel bits for a received transport block (TB) based on the determined maximum number of DL HARQ processes for the second serving cell.

2. The method of claim 1, wherein the DL reference timing for the second serving cell is a DL reference timing of the TDD UL-DL configuration of the first serving cell.

3. The method of claim 2, wherein the TDD UL-DL configuration of the first serving cell is a DL reference UL-DL configuration for the second serving cell.

4. The method of claim 2, wherein, when the TDD UL-DL configuration of the first serving cell is 1, the maximum number of DL HARQ processes for the second serving cell is set as 11.

5. The method of claim 2, wherein, when the TDD UL-DL configuration of the first serving cell is 2, the maximum number of DL HARQ processes for the second serving cell is set as 12.

6. The method of claim 2, wherein, when the TDD UL-DL configuration of the first serving cell is 3, the maximum number of DL HARQ processes for the second serving cell is set as 15.

7. The method of claim 2, wherein, when the TDD UL-DL configuration of the first serving cell is 4, the maximum number of DL HARQ processes for the second serving cell is set as 16.

8. The method of claim 2, wherein, when the TDD UL-DL configuration of the first serving cell is 5, the maximum number of DL HARQ processes for the second serving cell is set as 16.

9. The method of claim 1, wherein the soft channel bits are calculated by the following equation:

10. A method of performing a Hybrid Automatic Repeat reQuest (HARQ) operation by a user equipment (UE), the method comprising:

establishing a Radio Resource Control (RRC) connection with a base station through a first serving cell, the first serving cell supporting a Time Division Duplex (TDD) mode, and a TDD uplink(UL)-downlink(DL) configuration of the first serving cell being one of 1, 2, 3, 4, and 5;

receiving an RRC message from the base station through the first serving cell, the RRC message comprising carrier aggregation (CA) configuration information, the CA configuration information comprising information of a second serving cell supporting a Frequency Division Duplex (FDD) mode, and the first serving cell and the second serving cell being aggregated by a TDD-FDD CA scheme;

determining a maximum number of DL HARQ processes for the second serving cell according to the TDD UL-DL configuration of the first serving cell, the maximum number of DL HARQ processes for the second serving cell being greater than 8; and

storing soft channel bits for a received transport block (TB) based on the determined maximum number of DL HARQ processes for the second serving cell.