HARQ-ACK Codebook Segmentation for Flexible Transmission Timings

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Solution Overview

Problem

In future radio communication systems like LTE Rel.15 and 5G, the flexible configuration of HARQ-ACK transmission timings can lead to deterioration in communication quality due to inappropriate generation of HARQ-ACK codebooks when multiple HARQ-ACKs are transmitted in the same slot.

Innovation Solution

The solution involves controlling the generation of HARQ-ACK codebooks based on transmission timings and PUCCH resources notified by DCI, ensuring that HARQ-ACKs are set in the same codebook when their transmission timings are the same, and in different codebooks when their resources are different, to optimize communication efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If HARQ-ACK transmission timing is configured flexibly using DCI, then communication adaptability is improved, but HARQ-ACK codebook generation reliability deteriorates when multiple HARQ-ACKs are transmitted in the same slot

Engineering Contradiction:

ImproveHARQ-ACK transmission timing flexibilityVSAvoidHARQ-ACK codebook generation reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments HARQ-ACK codebooks into multiple independent codebooks based on different PUCCH resource groups. When multiple HARQ-ACKs are transmitted in the same slot, each HARQ-ACK is assigned to a separate codebook segment, preventing generation conflicts and ensuring reliable codebook formation while maintaining flexible transmission timing configuration.

Inventive Principle:

Principle #1Segmentation

2Productivity

If multiple HARQ-ACKs are transmitted in the same slot, then transmission efficiency is improved, but codebook generation complexity increases

Engineering Contradiction:

ImproveHARQ-ACK transmission efficiencyVSAvoidCodebook generation complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the codebook generation process into multiple independent segments, each corresponding to a specific PUCCH resource group. This segmentation allows parallel processing of different HARQ-ACK codebooks, reducing the overall generation complexity while enabling efficient simultaneous transmission of multiple HARQ-ACKs in the same slot.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different codebook generation rules to different PUCCH resource groups based on their local characteristics. Each resource group has its own codebook generation logic, allowing the system to handle multiple HARQ-ACKs with different requirements in the same slot without increasing overall complexity.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP3793282B1User terminal and wireless communication method

Publication Date: 2025.01.01 NTT DOCOMO INC

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AI summary

To appropriately generate HARQ-ACK codebook even when transmission timings of delivery confirmation signals are configured flexibly, a user terminal according to an aspect of the present disclosure includes a transmitting section that transmits a delivery confirmation signal for a downlink shared channel, based on downlink control information used for scheduling the downlink shared channel, and a control section that determines codebook for the delivery confirmation signal, based on at least one of a transmission slot of the delivery confirmation signal and an uplink control channel resource for the delivery confirmation signal that are indicated by the downlink control information.