US 9191180

US Patent 9,191,180: Summary and Independent Claims Overview

Title: Method and device for executing HARQ in TDD-based wireless communication system

Assignee: LG Electronics Inc.

Inventors: Dong Youn Seo, Min Gyu Kim, Han Byul Seo, Joon Kui Ahn, Suck Chel Yang

Filing Date: March 21, 2012

Issue Date: November 17, 2015

Abstract: Provided are a method and a device for executing a hybrid automatic repeat request (HARQ) of a terminal in a time division duplex (TDD)-based wireless communication system. The method comprises the steps of: receiving an uplink grant for a first subframe of a second serving cell through a first serving cell; transmitting uplink data in the first subframe on the basis of the uplink grant; receiving an acknowledgement/not-acknowledgement (ACK/NACK) for the uplink data through the first serving cell; and, when the ACK/NACK signal is a NACK, transmitting a retransmission data for the uplink data in a second subframe of the second serving cell.

Plain-Language Overview of Independent Claims:

US Patent 9,191,180 has three independent claims: Claim 1, Claim 11, and Claim 12.

Independent Claim 1:
This claim describes a method for a user equipment (UE) to perform Hybrid Automatic Repeat reQuest (HARQ) in a Time Division Duplex (TDD) wireless communication system where the UE is allocated multiple serving cells. The key aspects are:

• The UE receives an uplink grant for a first subframe of a second serving cell via a first serving cell.
• The UE sends uplink data in that first subframe based on the grant.
• The UE receives an ACK/NACK signal for that uplink data via the first serving cell.
• If the signal is NACK, the UE retransmits the data in a second subframe of the second serving cell.
• A critical condition is that the first serving cell and the second serving cell use different Uplink-Downlink (UL-DL) configurations, where a UL-DL configuration defines whether each subframe in a TDD frame is uplink or downlink.

Independent Claim 11:
This claim also describes a method for a UE to perform HARQ in a TDD-based wireless communication system with multiple serving cells. It is similar to Claim 1 but focuses on the grant and data transmission/reception, rather than explicit retransmission:

• The UE receives a grant for a first subframe of a second serving cell via a first serving cell.
• The UE sends data in that first subframe based on the grant.
• The UE receives an ACK/NACK signal for that data via the first serving cell.
• Again, the first serving cell and second serving cell utilize different UL-DL configurations.
• It further specifies that either the first UL-DL configuration (of the first serving cell) or the second UL-DL configuration (of the second serving cell) may have the same regression period of an HARQ process. Alternatively, the first and second UL-DL configurations may have the same DL-UL switch-point periodicity.

Independent Claim 12:
This claim details a method for a UE performing HARQ in a TDD system with multiple serving cells, focusing on how retransmission information is conveyed.

• The UE receives an uplink grant for a first subframe of a second serving cell via a first serving cell.
• The UE sends first UL data in the first subframe based on this grant.
• The UE then receives a second uplink grant for a second subframe of the second serving cell, also in the first serving cell. This second uplink grant includes information indicating whether the first UL data should be retransmitted or if new data should be sent.
• The UE sends second UL data in the second subframe based on the second uplink grant. If the information indicates retransmission, the second UL data is retransmission data of the first UL data; if it indicates new transmission, the second UL data is new UL data.
• Crucially, the subframe of the first serving cell where the second uplink grant is received does not include physical hybrid-ARQ indicator channel (PHICH) resources. This implies an alternative mechanism for acknowledging or requesting retransmission.
• Similar to the other claims, the first serving cell and second serving cell use different UL-DL configurations.

No results were found in the CAFC 2026 dockets for patent number 9191180 specifically.