HARQ-ACK Codebook Generation for Repeated DCI Scheduling

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The challenge in wireless communication systems is ensuring that network devices correctly receive hybrid automatic repeat request (HARQ) acknowledgement (ACK) feedback information, as existing methods may lead to incorrect decoding due to inconsistent or missed detection of downlink control information (DCI) scheduling the same transport block.

Innovation Solution

The proposed solution involves generating a HARQ-ACK codebook based on multiple DCI detections with associated DAI indications, ensuring consistent feedback bits by aligning the DCI scheduling the same transport block across different monitoring occasions, and adjusting PUCCH resources dynamically to improve reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If DCI is transmitted on multiple PDCCH monitoring occasions to improve reliability, then transmission reliability is improved, but the complexity of HARQ-ACK codebook generation increases due to inconsistent DAI indications

Engineering Contradiction:

ImproveDCI transmission reliabilityVSAvoidHARQ-ACK codebook generation complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The terminal device pre-determines a first PDCCH monitoring occasion from multiple monitoring occasions before generating the HARQ-ACK codebook. This preliminary selection establishes a reference point for consistently determining DAI indication values, thereby simplifying the codebook generation process while maintaining the reliability benefits of multi-occasion DCI transmission

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies different processing rules to different PDCCH monitoring occasions by selecting one specific occasion (the first one) as having special status. The DAI indication value is determined based on this selected monitoring occasion, creating a localized reference point that resolves the inconsistency problem across multiple monitoring occasions

Inventive Principle:

Principle #3Local quality

2Quantity of substance

If the terminal device determines HARQ-ACK codebook based on DAI indication from multiple DCI, then feedback coverage is improved, but decoding accuracy deteriorates due to inconsistent DAI values

Engineering Contradiction:

ImproveHARQ-ACK feedback coverageVSAvoidHARQ-ACK decoding accuracy

Core Design Contradiction:

Quantity of substanceVSMeasurement precision

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of trying to reconcile or average multiple different DAI indication values from different monitoring occasions, the patent inverts the approach by selecting one monitoring occasion (the first one) and using only its DAI indication value. This inversion from multi-value synthesis to single-value selection resolves the inconsistency and ensures accurate decoding

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS12598030B2Communication method and apparatus

Publication Date: 2026.04.07 HUAWEI TECH CO LTD

AI summary

A terminal device detects first DCI on a first PDCCH monitoring occasion, detects second DCI on a second PDCCH monitoring occasion, generates a hybrid automatic repeat request acknowledgement HARQ-ACK codebook based on the first PDCCH monitoring occasion and a DAI indication carried in at least one of the first DCI and the second DCI, and sends the HARQ-ACK codebook. The first DCI and the second DCI are for scheduling a same transport block TB, and the first DCI and the second DCI carry a same downlink assignment index DAI indication.