HARQ-ACK Feedback Time Determination in Semi-Persistent Scheduling

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Solution Overview

Problem

In new radio (NR) systems, semi-persistent scheduling for downlink transmission does not allow configuration of HARQ-ACK feedback time in non-initial scheduling, leading to inefficiencies and potential timing collisions due to the lack of DCI signaling interaction.

Innovation Solution

A method for determining HARQ-ACK feedback time in terminal devices using target signaling that carries HARQ-ACK feedback time parameters, allowing configuration even in non-initial scheduling by activating semi-persistent scheduling based on received downlink control signaling, and determining the feedback time based on the provided parameters and time-domain resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If semi-persistent scheduling is adopted for downlink transmission, then scheduling signaling overhead is reduced, but HARQ-ACK feedback time cannot be configured in non-initial scheduling

Engineering Contradiction:

Improvescheduling signaling overheadVSAvoidHARQ-ACK feedback time configuration capability

Core Design Contradiction:

Loss of energyVSAdaptability or versatility

Solution Approach 1:

The base station pre-configures a set of HARQ-ACK feedback time parameter sets through higher layer signaling (RRC signaling) before semi-persistent scheduling operations. This preliminary configuration enables the UE to determine HARQ-ACK feedback times in non-initial scheduling without requiring additional DCI signaling interaction, thus maintaining low overhead while enabling adaptability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces dynamic selection of HARQ-ACK feedback time parameters from pre-configured sets based on scheduling conditions. The UE can dynamically determine appropriate feedback timing by selecting from multiple parameter sets according to the specific scheduling scenario, enabling flexible adaptation without increasing signaling overhead.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If DCI signaling interaction is performed in each scheduling, then HARQ-ACK feedback time can be configured dynamically, but scheduling signaling overhead increases greatly

Engineering Contradiction:

ImproveHARQ-ACK feedback time configuration capabilityVSAvoidscheduling signaling overhead

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent extracts the HARQ-ACK feedback time parameter configuration from the DCI signaling and moves it to higher layer signaling (RRC signaling). This separation allows the feedback time parameters to be pre-configured once, and then reused across multiple semi-persistent scheduling operations without requiring repeated DCI interactions, significantly reducing signaling overhead while maintaining configuration capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The pre-configured HARQ-ACK feedback time parameter sets serve multiple scheduling instances universally. Once configured through RRC signaling, these parameter sets can be applied across multiple semi-persistent scheduling operations, making the configuration mechanism universal and eliminating the need for repeated DCI signaling for each scheduling event.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If HARQ-ACK feedback time is not configured in non-initial scheduling, then scheduling complexity is reduced, but timing collisions occur and scheduling efficiency decreases

Engineering Contradiction:

Improvescheduling signaling interaction complexityVSAvoidscheduling efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

By pre-configuring HARQ-ACK feedback time parameters through RRC signaling before semi-persistent scheduling operations, the system eliminates the need for complex DCI signaling interactions during each scheduling event. This preliminary configuration reduces scheduling complexity while preventing timing collisions, as the UE has advance knowledge of when to provide feedback.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent establishes a feedback mechanism where the base station pre-notifies the UE about HARQ-ACK feedback timing through RRC signaling. This feedback configuration enables the UE to proactively prepare for feedback transmission at the correct time, avoiding timing collisions and improving scheduling efficiency without requiring complex real-time signaling interactions.

Inventive Principle:

Principle #23Feedback

Data Source

PatentEP3726765B1HARQ-ACK feedback time determination method and terminal device

Publication Date: 2023.10.04 VIVO MOBILE COMM CO LTD

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AI summary

A method for determining a HARQ-ACK feedback time, a method for indicating a HARQ-ACK feedback time, a terminal device, and a network device are provided. The method includes: receiving a downlink control signaling, wherein the downlink control signaling carries a HARQ-ACK feedback time parameter, and the downlink control signaling is used to activate a downlink semi-persistent scheduling configuration; receiving semi-persistent scheduling data for downlink transmission on a first time-domain resource; and determining the HARQ-ACK feedback time of the semi-persistent scheduling data for the downlink transmission, based on the HARQ-ACK feedback time parameter and the first time-domain resource.