SPS HARQ-ACK Bit Order for 5G IoT Reliability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The 5G mobile communication system lacks a specified mechanism for organizing HARQ-ACK bit order in Semi-Persistent Scheduling (SPS) Physical Downlink Shared Channel (PDSCH) resources, hindering feedback on downlink reception correctness for Industry IoT devices.

Innovation Solution

A codebook HARQ-ACK bit order mechanism is introduced, where user equipment determines the order of HARQ-ACK bits based on time-domain position, component carrier index, and configuration index for each SPS PDSCH resource, enabling accurate feedback to the base station through a Physical Uplink Control Channel (PUCCH) resource.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple SPS PDSCH resources are configured for Industry IoT devices with periodic transmission requirements, then the system can meet diverse traffic types and latency requirements, but the HARQ-ACK feedback mechanism becomes undefined and unreliable

Engineering Contradiction:

Improvesupport for multiple traffic types and latency requirementsVSAvoidHARQ-ACK feedback reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the HARQ-ACK codebook into multiple groups, where each group corresponds to a specific SPS PDSCH resource configuration. This segmentation allows the system to maintain separate feedback mechanisms for different traffic types and latency requirements, ensuring that each group's HARQ-ACK bits are independently organized and transmitted, thereby resolving the reliability issue while preserving adaptability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces new parameters including a group indicator field in DCI format, codebook group index, and specific bit ordering rules within each codebook group. These parameter changes enable the system to dynamically adjust the feedback mechanism according to different SPS configurations, allowing reliable HARQ-ACK transmission for multiple traffic types simultaneously

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If HARQ-ACK bits for multiple SPS PDSCH resources are organized in a single codebook, then feedback transmission is simplified, but the system cannot provide accurate reception correctness feedback for specific SPS resources

Engineering Contradiction:

Improvefeedback transmission simplicityVSAvoiddownlink reception correctness accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent divides the HARQ-ACK codebook into multiple groups, with each group containing HARQ-ACK bits specific to particular SPS PDSCH resources. This segmentation maintains the simplicity of single-codebook transmission while enabling precise identification of which SPS resource each acknowledgment corresponds to, through the inclusion of group indicators and resource-specific bit positioning

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces intermediary elements including group indicator fields and codebook group indexes that act as mediators between the simplified codebook structure and the specific SPS resources. These intermediaries enable the system to map aggregated HARQ-ACK bits back to their corresponding SPS resources accurately, preserving both transmission simplicity and feedback precision

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If no specific bit ordering rule is defined for SPS HARQ-ACK bits, then the codebook structure remains flexible, but the base station cannot correctly interpret the feedback from user equipment

Engineering Contradiction:

Improvecodebook structure flexibilityVSAvoidfeedback interpretation accuracy

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent establishes specific parameter-based ordering rules for HARQ-ACK bits within each codebook group, using parameters such as SPS configuration index, service type identifier, and latency requirement level. These ordering rules provide a deterministic mapping between bit position and SPS resource, enabling the base station to correctly interpret feedback while maintaining flexibility through parameter-based adaptation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies preliminary ordering rules to HARQ-ACK bits during codebook construction, organizing bits in a predetermined sequence based on SPS resource characteristics before transmission. This preliminary organization ensures that when the base station receives the codebook, the bit ordering is already optimized for correct interpretation, eliminating ambiguity while preserving structural flexibility

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11777657B2User equipment and base station for mobile communication system

Publication Date: 2023.10.03 INSTITUTE FOR INFORMATION INDUSTRY

AI summary

A user equipment (UE) and a base station (BS) are provided. The UE monitors a plurality of semi-persistent scheduling (SPS) physical downlink shared channel (PDSCH) resources, and determines an SPS Hybrid Automatic Repeat reQuest acknowledge (HARQ-ACK) bit order of a plurality of SPS HARQ-ACK bits, corresponding to the SPS PDSCH resources, in a codebook according to a time-domain position, a component carrier index and a configuration index of each SPS PDSCH resource. Afterwards, the UE generates an HARQ-ACK message including the codebook according to the SPS HARQ-ACK bit order, and transmits the HARQ-ACK message on a physical uplink control channel (PUCCH) resource to the BS.