# US 2019/0356456 A1 · Apparatus and method for performing hybrid automatic repeat request operation in wireless communication system supporting carrier aggregation

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- Number: US 2019/0356456 A1
- Document ID: US20190356456A1
- Status: Published application
- Kind: A1
- Application number: 16/525,292
- Filed: 2019-07-29
- Published: 2019-11-21
- Earliest claimed: 2015-11-06
- Assignees: Innovative Technology Lab Co., Ltd.
- Applicants: Innovative Technology Lab Co., Ltd.
- Inventors: Dong Hyun PARK
- Web page: https://patentgrep.com/patent/US20190356456A1

## CPC

- H04L 1/0073: {Special arrangements for feedback channel}
- H04L 5/0055: {Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861)}
- H04B 7/0413: MIMO systems
- 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)}
- H04L 1/1607: Details of the supervisory signal
- H04L 1/1812: Hybrid protocols; Hybrid automatic repeat request [HARQ]
- H04L 1/1887: {Scheduling and prioritising arrangements}
- H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal
- H04L 5/001: {the frequencies being arranged in component carriers}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H04B: TRANSMISSION
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

Provided is a method of performing HARQ by a UE in a wireless communication system that supports carrier aggregation (CA). The method includes: receiving, from an evolved nodeB (eNB), a downlink grant on a first Physical Downlink Control Channel (PDCCH), the downlink grant including an accumulated downlink assignment indicator (A-DAI) field and a total DAI (T-DAI) field; receiving a first PDSCH indicated by the first PDCCH, the first PDSCH being transmitted from the eNB; receiving, from the eNB, an uplink grant on a second PDCCH, the uplink grant indicating a transmission of a Physical Uplink Shared Channel (PUSCH); determining a size of a HARQ-ACK codebook to which a HARQ-ACK with respect to the first PDSCH is to be mapped, based on the A-DAI and the T-DAI; and transmitting, to the eNB, the HARQ-ACK with respect to the first PDSCH on the PUSCH.

## Claims

### Claim 1

A method comprising:
receiving, by a user equipment (UE), from a first serving cell, and via a first Physical Downlink Control Channel (PDCCH) in a first subframe, a first downlink grant comprising a first accumulated downlink assignment indicator (A-DAI) field and a first total DAI (T-DAI) field;
receiving, by the UE, from a second serving cell, and via a second PDCCH in the first subframe, a second downlink grant comprising a second A-DAI field and a second T-DAI field;
determining a value of the first A-DAI field and a value of the first T-DAI field, wherein the value of the first T-DAI field indicates an integer T1, wherein the value of the first A-DAI field indicates an integer A smaller than or equal to the integer T1, and wherein the value of the first T-DAI field is mapped to a set including a plurality of T-DAI values;
determining a value of the second A-DAI field and a value of the second T-DAI field, wherein the value of the second T-DAI field indicates the integer T1, and wherein the value of the second A-DAI field indicates an integer B smaller than or equal to the integer T1;
receiving a first PDSCH indicated by the first PDCCH and receiving a second PDSCH indicated by the second PDCCH;
determining that the integer B is the highest value among values indicated by A-DAI field values determined from PDCCHs received in the first subframe;
determining one of the plurality of T-DAI values, which is the closest integer to the integer B;
receiving an uplink grant indicating a transmission of a Physical Uplink Shared Channel (PUSCH);
determining a size of a hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook to which an HARQ-ACK associated with the first PDSCH and an HARQ-ACK associated with the second PDSCH are to be mapped, wherein the size of the HARQ-ACK codebook is determined based on the determined one of the plurality of T-DAI values; and
transmitting, via the PUSCH, the HARQ-ACK associated with the first PDSCH and the HARQ-ACK associated with the second PDSCH