Uplink HARQ Feedback Segmentation for Multiple SPS Configurations

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Solution Overview

Problem

Existing communication systems face challenges in efficiently managing hybrid automatic repeat request (HARQ) feedback for downlink semi-persistent scheduling (SPS) configurations, particularly with shorter periodicities and multiple configurations, leading to inefficiencies in uplink control information transmission.

Innovation Solution

A method for wireless transmit/receive units (WTRUs) that involves receiving downlink SPS configurations, determining HARQ feedback bits, segmenting them based on triggering conditions, and transmitting the determined portions using uplink channels, optimizing HARQ feedback for multiple SPS configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple downlink SPS configurations with shorter periodicities are supported, then the system capacity and resource utilization are improved, but the uplink control overhead and complexity increase

Engineering Contradiction:
Improvesystem capacityVSAvoiduplink control overhead
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent segments the HARQ feedback bits into multiple groups, where each group corresponds to a subset of downlink SPS transmissions. This segmentation allows the WTRU to transmit only the necessary feedback information for active SPS configurations, reducing overall uplink control overhead while maintaining support for multiple SPS configurations with shorter periodicities

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements partial action by determining that at least a portion of the HARQ feedback bits needs to be transmitted based on triggering conditions. Instead of transmitting all possible feedback bits for all configured SPS configurations, the system transmits only the portion corresponding to actual downlink transmissions, thereby reducing overhead while maintaining system capacity

Inventive Principle:
Principle #16Partial or excessive action

2Productivity

If multiple downlink SPS configurations are supported, then the resource utilization is improved, but the device complexity increases

Engineering Contradiction:
Improveresource utilizationVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the HARQ feedback into multiple groups based on downlink SPS configuration indices, allowing the WTRU to independently manage feedback for each configuration. This segmentation simplifies the processing complexity by organizing feedback handling into discrete, manageable units rather than requiring complex unified processing for all configurations

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter of feedback transmission by determining at least a portion of HARQ feedback bits based on triggering conditions and downlink SPS configurations. This dynamic parameter adjustment allows the system to adapt feedback transmission to actual network conditions, reducing complexity compared to always transmitting full feedback for all configurations

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If HARQ feedback bits are segmented and only portion transmitted, then the uplink overhead is reduced, but the measurement precision of feedback information may be affected

Engineering Contradiction:
Improveuplink overheadVSAvoidfeedback information precision
Core Design Contradiction:
Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent extracts and transmits only the necessary portion of HARQ feedback bits corresponding to actual downlink SPS transmissions. By taking out only the relevant feedback information rather than transmitting all possible feedback bits, the system reduces uplink overhead while maintaining sufficient feedback precision for active transmissions

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements a feedback mechanism where the WTRU determines at least a portion of HARQ feedback bits based on triggering conditions. This feedback approach ensures that essential acknowledgment information is transmitted to enable retransmissions when needed, maintaining measurement precision for critical feedback while reducing overall overhead

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4104336B1Methods and apparatus for uplink control enhancement
Publication Date: 2025.09.03 INTERDIGITAL PATENT HOLDINGS INC
  • EP4104336B1 patent drawingFigure 1A
  • EP4104336B1 patent drawingFigure 1B
  • EP4104336B1 patent drawingFigure 1C

AI summary

Methods and apparatus for uplink control enhancement in wireless communications are disclosed. In an example, a method includes receiving information related to a set of downlink SPS configurations, receiving downlink SPS transmission(s) based on the received information, determining a payload of UCI for transmission over an uplink channel, the payload comprises a set of HARQ feedback bits based on the received information, determining that at least one triggering condition for segmenting the set of HARQ feedback bits is satisfied, determining at least a portion of the set of HARQ feedback bits based on at least a downlink SPS configuration of the set of downlink SPS configurations, wherein the determined portion of the set of HARQ feedback bits corresponds to a respective subset of the received downlink SPS transmission(s), and transmitting at least the determined portion of the set of HARQ feedback bits using the uplink channel.