Group Common DCI HARQ Feedback for NR-U

Solution Overview

Problem

Current wireless communication systems face inefficiencies in uplink transmission in unlicensed spectrum due to high latency and channel access contention, particularly in providing HARQ feedback, which affects resource utilization and coexistence with other technologies.

Innovation Solution

A method involving the transmission of HARQ acknowledgement feedback in a group common downlink control information format to a dynamically selected subset of user equipment (UEs), using a semi-statically configured codebook, which reduces signaling overhead and latency by grouping UEs with shared resources and providing feedback simultaneously.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If HARQ feedback is transmitted individually to each UE in unlicensed spectrum, then each UE receives its feedback, but signaling overhead and channel access contention increase

Engineering Contradiction:

ImproveHARQ feedback deliveryVSAvoidsignaling overhead

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent combines HARQ feedback for multiple UEs into a single group common DCI message. The base station groups multiple UEs and transmits their HARQ acknowledgments simultaneously in one downlink transmission, thereby reducing the number of separate channel access attempts and lowering signaling overhead while ensuring all grouped UEs receive their feedback.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If HARQ feedback is transmitted individually to each UE, then each UE receives its feedback, but latency increases due to multiple channel access attempts

Engineering Contradiction:

ImproveHARQ feedback deliveryVSAvoidlatency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent combines HARQ feedback for multiple UEs into a single group common DCI message. The base station groups multiple UEs and transmits their HARQ acknowledgments simultaneously in one downlink transmission, thereby reducing the number of separate channel access attempts and lowering signaling overhead while ensuring all grouped UEs receive their feedback.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of operation

If HARQ feedback is transmitted to all UEs in a group, then all UEs receive feedback, but overhead increases for UEs not needing feedback

Engineering Contradiction:

Improvefeedback transmission simplicityVSAvoidsignaling overhead

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The patent segments the group common DCI message into individual feedback fields for each UE. Each UE can identify its specific feedback portion within the group message and process only relevant information. This segmentation allows efficient group-wide feedback transmission while enabling UEs to ignore unnecessary feedback data, reducing effective overhead for each UE.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11632195B2Method for transmission of HARQ feedback in group common downlink control information

Publication Date: 2023.04.18 HUAWEI TECH CO LTD

AI summary

Aspects of the present disclosure may involve introducing a new downlink feedback information codebook design, a new downlink control information (DCI) format, associated radio resource control (RRC) configuration parameters and UE procedures that can be used in New Radio Unlicensed (NR-U). In some embodiments, the DFI codebook may be of use for providing HARQ feedback with configured grant transmissions. Some embodiments of the disclosure may aid in reducing signaling overhead by grouping HARQ-ACK feedback from a dynamically selected number of UEs.