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.](/litigations/by-plaintiff/LG%20Electronics%20Inc.)

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.

No litigation is known involving US patent 9191180 based on the conducted search. The search results did not yield any specific court cases or PTAB challenges for this particular patent number.

Proceedings overview

There are no PTAB proceedings on file for US patent 9191180. This means the patent has not been challenged through Inter Partes Review (IPR), Post-Grant Review (PGR), or Covered Business Method (CBM) review. This gives a defendant less clarity regarding the patent's strength against prior art challenges in the PTAB forum.

Strategic summary

Currently, all claims of US patent 9191180 remain untested in the context of AIA trial proceedings. There is no estoppel landscape established through PTAB trials, meaning a potential defendant is not barred from raising any prior-art grounds in a future IPR, PGR, or CBM. The absence of PTAB activity suggests that, while the patent is active, it has not yet faced the scrutiny of these specific post-grant challenges.

Recommended next steps

Since no PTAB activity exists for US patent 9191180, a defendant facing assertion of this patent should consider initiating an AIA trial proceeding, such as an IPR, to challenge the patentability of the claims based on prior art. This would provide an opportunity to potentially invalidate claims and strengthen a defensive position.

Inventors

• Dong Youn Seo ([LG Electronics Inc.](/litigations/by-plaintiff/LG%20Electronics%20Inc.))
• Min Gyu Kim (LG Electronics Inc.)
• Han Byul SEO (LG Electronics Inc.)
• Joon Kui Ahn (LG Electronics Inc.)
• Suck Chel Yang (LG Electronics Inc.)

Original assignee

LG Electronics Inc. is the original assignee. LG Electronics Inc. is a multinational electronics company that manufactures and ships a wide range of products, including mobile phones, televisions, home appliances, and vehicle components. They are an operating company. LG Electronics Inc. is currently operating.

Assignment timeline

The USPTO Patent Assignment Search shows one assignment record for US9191180:

• 2013-11-27 (executed) / recorded 2013-11-27 — Reel 031383/0947
  • Conveyance: Assignment of Assignors Interest
  • Assignor: KIM, MIN GYU; AHN, JOON KUI; SEO, DONG YOUN; SEO, HAN BYUL; YANG, SUCK CHEL
  • Assignee: LG ELECTRONICS INC.
  • Correspondent: BIRCH STEWART KOLASCH & BIRCH, LLP (address not specified, but firm is a known patent prosecution firm).
  • Context: Internal reorg (assignment from individual inventors to the corporate entity).

Timeline diagram

timeline
    title Ownership of US 9191180
    2012 : Application filed by LG Electronics Inc
    2013 : Assigned to LG Electronics Inc
    2015 : Issued to LG Electronics Inc

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The sole assignee, LG Electronics Inc., is a well-established operating company that manufactures and sells products. The assignment is from the inventors to this operating company.
2. Known asserter in the chain — not present. LG Electronics Inc. is not identified as a known NPE.
3. Repeat correspondent across the chain — not present. Only one assignment is recorded, and the correspondent, BIRCH STEWART KOLASCH & BIRCH, LLP, is a standard patent prosecution firm.
4. Cascading transfers — not present. Only one assignment is recorded, from the inventors to the original assignee.
5. Pre-litigation transfer — not present. There are no recorded infringement suits for this patent, and the assignment occurred well before the patent's issuance.
6. Bankruptcy fire-sale — not present. There is no indication that LG Electronics Inc. has filed for bankruptcy.
7. Privateering — not present. There is no evidence to suggest this patent was transferred to an NPE for assertion on behalf of LG Electronics Inc.
8. Defensive aggregator (anti-NPE) — not present. The patent is currently assigned to LG Electronics Inc., which is not a defensive aggregator.

Verdict

Insufficient data (only the original assignment). The single recorded assignment is from the individual inventors to LG Electronics Inc., the original operating company assignee. There are no subsequent transfers or other signals that would indicate NPE activity.

USPTO Patent Assignment Search for US9191180

Prior Art Analysis for US Patent 9191180

The following analysis focuses on identifying and describing the most relevant prior art cited in US Patent 9191180, titled "Method and device for executing HARQ in TDD-based wireless communication system." The selection prioritizes patent publications with dates preceding the priority date of US9191180 (March 21, 2011) and those whose titles suggest a focus on Hybrid Automatic Repeat Request (HARQ) and Time Division Duplex (TDD) systems. Due to the volume of cited prior art, a representative selection is presented, with an emphasis on the distinguishing feature of US9191180, which is HARQ operation in a TDD system with multiple serving cells utilizing different Uplink-Downlink (UL-DL) configurations.

The main independent claims of US9191180 describe a method and user equipment (UE) for performing HARQ involving a first serving cell and a second serving cell that use different UL-DL configurations. This multi-cell, differing UL-DL configuration aspect is central to the invention.

Here are selected prior art patents cited in US9191180:

1. US20100067460A1

• Full Citation: US20100067460A1, "Method and apparatus for transmitting control information in wireless communication system"
• Publication/Filing Date: Published: March 18, 2010.
• Brief Description: This patent application describes a method and apparatus for transmitting uplink control information (UCI) in a wireless communication system, specifically addressing situations where a user equipment (UE) transmits both acknowledgement/negative-acknowledgement (ACK/NACK) and Channel Quality Indicator (CQI) information in a single uplink subframe. The invention focuses on efficiently multiplexing these different types of control information on a Physical Uplink Control Channel (PUCCH) or Physical Uplink Shared Channel (PUSCH) by determining the number of ACK/NACK bits and then selecting a PUCCH format or PUSCH resource. It also considers the transmission of an ACK/NACK signal for a Physical Downlink Shared Channel (PDSCH) or a scheduling request (SR).
• Potential Anticipation under 35 U.S.C. § 102: US20100067460A1 broadly addresses the transmission of uplink control information, including HARQ ACK/NACK, in a wireless communication system. While it details mechanisms for multiplexing and transmitting control signals, its abstract and general description do not explicitly disclose the scenario of multiple serving cells operating with different UL-DL configurations in a TDD system, which is a key distinguishing feature of US9191180 (e.g., in claims 1, 10, 13, and 15). Therefore, this prior art would likely not anticipate the specific multi-cell, different UL-DL configuration aspects of US9191180's claims. It might anticipate general elements related to HARQ ACK/NACK transmission in TDD, but not the inventive combination of features.

2. US20110051659A1

• Full Citation: US20110051659A1, "Method and apparatus for transmitting uplink control information in a wireless communication system"
• Publication/Filing Date: Published: March 3, 2011.
• Brief Description: This patent application describes a method and apparatus for a user equipment (UE) to transmit uplink control information (UCI) in a wireless communication system. The method involves receiving downlink data on a Physical Downlink Shared Channel (PDSCH) or a Physical Downlink Control Channel (PDCCH) indicating semi-persistent scheduling (SPS) release, and subsequently transmitting an acknowledgement/negative-acknowledgement (ACK/NACK) signal in an uplink subframe. The invention specifically outlines how PUCCH resources for ACK/NACK transmission are allocated and determined, particularly when multiple downlink subframes are associated with a single uplink subframe in a TDD system, including handling of discontinuous transmission (DTX) and channel selection.
• Potential Anticipation under 35 U.S.C. § 102: US20110051659A1 is highly relevant to HARQ ACK/NACK transmission in TDD systems, particularly concerning the association of multiple downlink subframes with an uplink subframe for ACK/NACK feedback. It describes aspects like PUCCH resource allocation and channel selection in TDD. However, similar to US20100067460A1, its abstract does not clearly disclose the use of multiple serving cells, each employing a different UL-DL configuration, which is the central inventive concept of US9191180. While it anticipates elements of TDD HARQ timing and resource allocation for single-cell scenarios, it does not appear to anticipate the cross-carrier scheduling and different UL-DL configurations across cells as claimed in US9191180 (e.g., claims 1, 10, 13, 15).

3. US20110026466A1

• Full Citation: US20110026466A1, "Method for transmitting control information in wireless communication system"
• Publication/Filing Date: Published: February 3, 2011.
• Brief Description: This patent application details a method for a user equipment (UE) to transmit control information, specifically an acknowledgement/negative-acknowledgement (ACK/NACK) signal, in a wireless communication system. The method involves receiving physical downlink control channels (PDCCHs) that schedule physical downlink shared channels (PDSCHs) in multiple downlink subframes, and then transmitting a single bundled or multiplexed ACK/NACK signal for these multiple PDSCHs in a single uplink subframe. The invention describes how to determine the uplink subframe for transmission and the resources (e.g., PUCCH resources) to be used for the ACK/NACK signal, especially in a Time Division Duplex (TDD) environment where a single uplink subframe may correspond to multiple downlink subframes.
• Potential Anticipation under 35 U.S.C. § 102: US20110026466A1 focuses on efficient ACK/NACK transmission for multiple downlink transmissions in a TDD system, including techniques like bundling or multiplexing. This is a common challenge in TDD due to the asymmetry of uplink and downlink subframes. While highly relevant to TDD HARQ, the abstract does not indicate that it contemplates the scenario of carrier aggregation where different serving cells operate with different UL-DL configurations. Therefore, while it may anticipate aspects of HARQ processing, bundling, and timing within a single TDD cell context, it would not anticipate the specific inventive features of US9191180 related to HARQ coordination across multiple cells with divergent UL-DL configurations (e.g., claims 1, 10, 13, 15).

Summary of Anticipation

The examined prior art documents generally address the challenges of HARQ and uplink control information transmission in TDD wireless communication systems, particularly concerning the mapping of multiple downlink subframes to single uplink subframes for ACK/NACK feedback and efficient resource allocation. These disclosures provide foundational knowledge for TDD HARQ operations.

However, the core inventive contribution of US9191180 lies in addressing the problem of performing synchronous HARQ in a TDD system where a UE is allocated multiple serving cells (e.g., primary and secondary cells in carrier aggregation) that use different UL-DL configurations. The disclosed methods in US9191180 aim to resolve issues that arise from such divergent configurations, such as ensuring proper HARQ timing and process management. The abstracts of the reviewed prior art do not explicitly disclose this specific combination of features—i.e., multi-cell operation with different UL-DL configurations, and the specific HARQ adjustments necessitated by this difference. Therefore, while these prior art documents collectively establish the state of the art for TDD HARQ in a single-cell context, they do not appear to anticipate the specific claims of US9191180 related to harmonizing HARQ processes across multiple serving cells with heterogeneous UL-DL configurations under 35 U.S.C. § 102.

Obviousness Analysis of US Patent 9,191,180 under 35 U.S.C. § 103

This analysis will assess the obviousness of US Patent 9,191,180 by identifying potential combinations of prior art references and articulating the motivation a Person Having Ordinary Skill in the Art (PHOSITA) would have had to combine them. The effective filing date of US 9,191,180 is March 21, 2012.

Legal Standard for Obviousness

Under 35 U.S.C. § 103, a patent claim is obvious if "the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains." The Supreme Court in KSR International Co. v. Teleflex Inc. emphasized that obviousness can be established by combining or modifying prior art teachings where there is some teaching, suggestion, or motivation to do so. This motivation can come from the knowledge of those skilled in the art, from the prior art references themselves, or from the nature of the problem to be solved.

Prior Art References

The patent itself lists prior art keywords as "subframe," "serving cell," "data," "grant," and "harq."

1. US 9,137,804 B2 (Kim et al.) ("Kim '804"): Published on December 27, 2012 (though its PCT application, WO2011/115480 A2, was filed March 18, 2011, and claims priority to a US provisional application filed March 18, 2010), this patent explicitly discusses "Systems and Methods for supporting carrier aggregation with different TDD configurations." It addresses HARQ feedback mechanisms for both simultaneous and non-simultaneous DL/UL transceiving in such a scenario. Kim '804 illustrates an example where a Primary Cell (PCELL) has TDD configuration 1 and a Secondary Cell (SCELL) has TDD configuration 0, highlighting the challenge of HARQ feedback when PCELL subframes are downlink and lack UL resources. It also details that HARQ feedback may be transmitted via PUCCH or PUSCH.
2. "HARQ For Dynamic Change of the TTD UL/DL Configuration in LTE TDD Systems" (Mohanty et al.) ("Mohanty"): This article discusses HARQ in the context of dynamic TDD UL/DL configuration changes in LTE TDD systems. It highlights identifying different TDD UL/DL configurations for adjacent radio frames and discusses controlling the number of HARQ processes for PDSCH/PUSCH prior to reconfiguration. It also mentions sending an UL grant for PUSCH retransmission based on UL grant timing of the current configuration, potentially using DCI.
3. WO 2015/048404 A1 (Qualcomm Inc.) ("Qualcomm '404"): Published April 2, 2015 (International Filing Date: September 26, 2014), this patent application focuses on "REDUCED DELAY HARQ PROCESS TIMELINE FOR FDD-TDD CARRIER AGGREGATION." It describes methods for multi-carrier scheduling, including minimizing HARQ delay in networks using one or more TDD component carriers and one or more FDD component carriers. It also mentions determining the number of HARQ processes for a TDD component carrier based on its DL/UL configuration and that scheduling may involve overwriting certain HARQ transfers.
4. "Dynamic Uplink - Downlink Configuration in TD- LTE with HARQ Feedback" (Sharma et al.) ("Sharma"): This academic paper, while potentially published after the effective filing date (exact date not provided, but references include 2012-2016), discusses HARQ reference configurations for each serving cell in carrier aggregation for better effectiveness. It states that the HARQ reference configuration should not depend on the actual UL-DL configuration, making it robust against reconfiguration errors. It also notes that an UL subframe in the downlink HARQ reference configuration cannot be used for PDSCH transmissions because no UL HARQ acknowledgment timing is defined.
5. "HARQ Timing (Multiplexed Mode)" (Keysight) ("Keysight"): This document provides a timing diagram for LTE TDD uplink HARQ processes, noting that the number of UL HARQ processes depends on the UL/DL configuration. It explains that the eNB sends ACK/NACK after certain subframes, and based on this response, the UE sends new data or retransmits. It further details how PHICH can carry multiple HARQ ACK/NACKs depending on the UL/DL configuration.

Obviousness Combinations

The core inventive concept of US 9,191,180 lies in performing synchronous HARQ in a TDD-based carrier aggregation system where different UL-DL configurations are used across serving cells.

Combination 1: Kim '804 + Keysight + PHOSITA Common Knowledge

• Kim '804 clearly discloses the concept of carrier aggregation with different TDD UL-DL configurations for different serving cells (e.g., PCELL with TDD configuration 1 and SCELL with TDD configuration 0). It explicitly raises the problem of HARQ feedback mechanisms in such a scenario, noting that directly applying a standard HARQ feedback timetable can lead to issues where UL resources for feedback are unavailable in a particular cell. Kim '804 even suggests "smart scheduling" to avoid scheduling DL resources that would require HARQ feedback in an unavailable UL subframe.

• Keysight describes the fundamental principles of TDD uplink HARQ processes, including the dependence of the number of HARQ processes on the UL/DL configuration and the mechanism of ACK/NACK feedback leading to retransmission or new data transmission. It also explains how PHICH can carry multiple HARQ ACK/NACKs.

• Motivation to Combine: A PHOSITA, aware of the challenges identified in Kim '804 regarding HARQ feedback in carrier aggregation with different TDD UL-DL configurations, and possessing the general knowledge of TDD HARQ timing as described in Keysight, would have been motivated to find solutions for maintaining reliable HARQ operation. The problem itself—ensuring proper HARQ timing and feedback across cells with asynchronous UL/DL structures—would drive a PHOSITA to explore adaptations of existing HARQ mechanisms.

  Specifically, independent Claim 1, which involves receiving an UL grant for a second serving cell via a first serving cell, sending UL data in the first subframe of the second serving cell, receiving ACK/NACK via the first serving cell, and retransmitting in a second subframe of the second serving cell if NACK, all while using different UL-DL configurations, would be obvious. Kim '804 already discusses HARQ feedback mechanisms in carrier aggregation with different TDD configurations and shows PCELL being used for SCELL feedback concerns. The idea of an HARQ process involving initial transmission and retransmission in response to an ACK/NACK is fundamental to HARQ, as explained in Keysight. The adjustment of timing or process allocation to accommodate different UL-DL configurations, as presented in the problem statement of Kim '804, would be a natural engineering solution for a PHOSITA.

Combination 2: Kim '804 + Mohanty + PHOSITA Common Knowledge

• Kim '804 again establishes the context of carrier aggregation with differing TDD UL-DL configurations and the problem of HARQ feedback.

• Mohanty specifically addresses HARQ in the context of dynamic changes in TDD UL/DL configurations. It discusses identifying different UL/DL configurations for adjacent radio frames and controlling the number of HARQ processes. Crucially, it also mentions sending an UL grant for PUSCH retransmission based on UL grant timing, potentially using DCI (Downlink Control Information).

• Motivation to Combine: Given Kim '804's disclosure of the difficulties in managing HARQ across cells with static but different TDD UL-DL configurations, a PHOSITA would be motivated to look at solutions for managing HARQ in scenarios involving TDD configuration differences, including dynamic changes. Mohanty's teachings on controlling HARQ processes and using UL grants with DCI for retransmission in dynamic TDD environments would directly inform a PHOSITA's approach to solving the problems raised in Kim '804.

  This combination renders independent Claim 12 obvious. Claim 12 focuses on the retransmission information being included in a second uplink grant for a second subframe, where the subframe receiving this grant does not include PHICH resources. Mohanty teaches sending UL grants for PUSCH retransmission based on current UL grant timing using DCI. Kim '804 identifies the problem of PCELL subframes lacking UL resources for HARQ feedback from SCELL, implying the need for alternative feedback mechanisms or scheduling adjustments. A PHOSITA would recognize that if PHICH resources are unavailable (as described in Kim '804's problem scenario), including retransmission information directly in an UL grant (as suggested by Mohanty for DCI) would be an effective alternative to manage HARQ, rather than relying on a PHICH. This is a logical adaptation to solve the identified problem of scarce or misaligned UL feedback resources.

Combination 3: Kim '804 + Sharma + Keysight + PHOSITA Common Knowledge

• Kim '804 establishes the multi-cell TDD environment with different UL-DL configurations.

• Sharma discusses HARQ reference configurations for each serving cell in carrier aggregation and states that these configurations should be robust against UL-DL reconfiguration errors. It also points out that an UL subframe in a downlink HARQ reference configuration might not be usable for PDSCH transmission due to undefined UL HARQ acknowledgment timing.

• Keysight provides the basic understanding of HARQ timing and the dependence of HARQ processes on UL/DL configuration.

• Motivation to Combine: Facing the challenges of different UL-DL configurations and potential HARQ timing conflicts (as presented in Kim '804 and implied by Sharma's discussion of reference configurations), a PHOSITA would be motivated to harmonize or adapt HARQ processes across these cells. Sharma's concept of an HARQ reference configuration per serving cell, designed for robustness, directly addresses the underlying problem of managing HARQ in such complex scenarios. Combining this with the fundamental HARQ mechanisms from Keysight and the carrier aggregation context from Kim '804 would lead to the adaptations claimed in US 9,191,180.

  This combination makes independent Claim 11 obvious. Claim 11, similar to Claim 1, involves receiving a grant for a first subframe of a second serving cell via a first serving cell, sending data, and receiving an ACK/NACK, with different UL-DL configurations. It adds that either the first or second UL-DL configuration may have the "same regression period of an HARQ process" or the "same DL-UL switch-point periodicity." Sharma's discussion of HARQ reference configurations for each serving cell and their robustness against configuration changes implies a desire for stable and predictable HARQ timing (i.e., consistent regression periods or switch-point periodicity) even when underlying UL-DL configurations differ. A PHOSITA would understand the benefit of such consistency for efficient HARQ operation across aggregated carriers, especially when combining the known HARQ operations from Keysight and the multi-cell, differing TDD configurations from Kim '804. This would motivate a PHOSITA to design the system to achieve such consistent periodicity where possible or to define HARQ processes with a consistent regression period despite differing UL-DL configurations.

Conclusion

The claims of US Patent 9,191,180 would likely be found obvious over combinations of the identified prior art references. The references collectively disclose the essential elements of carrier aggregation, TDD systems, differing UL-DL configurations across cells, and the general principles of HARQ and its timing. The problems inherent in integrating HARQ into such a complex environment (e.g., ensuring timely ACK/NACK feedback, managing HARQ processes across disparate timing structures, and conveying retransmission information efficiently) would have provided ample motivation for a PHOSITA to combine and adapt the known teachings to arrive at the claimed inventions.