HARQ-ACK Sub-Codebook for DCI Without Downlink Assignment

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Solution Overview

Problem

Existing wireless communication systems face inefficiencies in handling hybrid automatic repeat request (HARQ-ACK) codebooks for downlink control information (DCI) without downlink assignments, leading to increased signaling overhead and unclear bit transmission protocols.

Innovation Solution

Implementing a first sub-codebook in a HARQ-ACK codebook for transmitting acknowledgement (ACK) or negative acknowledgement (NACK) bits for DCI not associated with downlink assignments, allowing ACK/NACK bits to be transmitted in a specific sub-codebook, thereby reducing signaling overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a unified HARQ-ACK codebook is used for all DCI types, then codebook management is simplified, but signaling overhead increases and transmission protocols become unclear

Engineering Contradiction:

ImproveHARQ-ACK codebook management complexityVSAvoidsignaling overhead

Core Design Contradiction:

Device complexityVSQuantity of substance

Solution Approach 1:

The patent divides the HARQ-ACK codebook into two distinct sub-codebooks: a first sub-codebook for DCI with downlink assignment and a second sub-codebook for DCI without downlink assignment. This segmentation allows separate management of different DCI types, reducing signaling overhead by enabling targeted acknowledgment transmission only when necessary, while maintaining clear transmission protocols for each sub-codebook type.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If ACK/NACK bits are transmitted without specific sub-codebook designation, then transmission flexibility is maintained, but protocol clarity decreases and inefficiencies arise

Engineering Contradiction:

Improvetransmission flexibilityVSAvoidprotocol clarity

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent applies local quality by assigning specific properties to different sub-codebooks: the first sub-codebook is designated for DCI with downlink assignment requiring detailed acknowledgment, while the second sub-codebook is designated for DCI without downlink assignment requiring simpler acknowledgment. This localized differentiation improves protocol clarity for each DCI type while maintaining overall transmission flexibility through the dual sub-codebook structure.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12526092B2Hybrid automatic repeat request acknowledgement codebook for downlink control information without downlink assignment

Publication Date: 2026.01.13 QUALCOMM INC

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a network node, downlink control information (DCI) not associated with a downlink assignment. The UE may transmit, to the network node, an acknowledgement (ACK) or negative acknowledgement (NACK) bit for the DCI not associated with the downlink assignment in a first sub-codebook of a hybrid automatic repeat request (HARQ)-ACK codebook. Numerous other aspects are described.