PUCCH Collision Resolution in NR Subslots

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Solution Overview

Problem

In wireless communication systems, particularly in the New Radio (NR) standard, physical uplink control channel (PUCCH) collisions occur in subslots, leading to overlapping resources that existing solutions, such as multiplexing, fail to resolve effectively due to the complexity of prioritization and timeline management across multiple subslots.

Innovation Solution

The method involves configuring PUCCH resources to avoid overlap by removing candidate resources that extend into subsequent subslots, prioritizing transmission based on relative priority, and utilizing a utility maximization function to ensure timely and efficient UCI message transmission, thereby preventing collisions and ensuring that only high-priority messages are retained for transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple PUCCH resources are configured in a slot to support faster HARQ-ACK feedback, then the productivity of feedback transmission is improved, but PUCCH collisions occur between subslots leading to resource overlap and transmission conflicts

Engineering Contradiction:

ImproveHARQ-ACK feedback transmission speedVSAvoidPUCCH transmission reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The slot is divided into multiple subslots, with each subslot containing at most one PUCCH that carries HARQ-ACK. This segmentation prevents PUCCH collisions by ensuring temporal separation of PUCCH transmissions within different subslots, while still allowing multiple PUCCH opportunities across the entire slot for faster feedback

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The network node determines and removes candidate PUCCH resources that would extend into subsequent subslots before collision resolution is needed. This preliminary action prevents potential collisions from occurring in the first place, ensuring reliable transmission while maintaining the ability to support multiple feedback opportunities

Inventive Principle:

Principle #10Preliminary action

2Quantity of substance

If PUCCH resources are allowed to extend across subslot boundaries to maximize resource utilization, then the quantity of available PUCCH resources is improved, but resource overlap and collisions occur between adjacent subslots

Engineering Contradiction:

Improveavailable PUCCH resourcesVSAvoidPUCCH collision interference

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

Candidate PUCCH resources that would extend into subsequent subslots are identified and removed from the set of available resources. This extraction eliminates the harmful overlap while preserving PUCCH resources that are properly contained within subslot boundaries, maintaining resource quantity without the collision harm

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The PUCCH resource configuration is made subslot-specific, where each subslot has its own set of candidate PUCCH resources determined based on local conditions. This allows optimal resource allocation within each subslot while preventing cross-subslot collisions, as each subslot's resources are independently managed

Inventive Principle:

Principle #3Local quality

3Ease of operation

If existing multiplexing rules from Release 15 are applied to resolve PUCCH collisions, then the ease of operation is maintained, but the solution fails to account for subslot-specific priorities and timeline requirements in Release 16

Engineering Contradiction:

Improvecollision resolution procedure simplicityVSAvoidsupport for different service priorities

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The collision resolution mechanism is made dynamic and adaptive to Release 16 requirements by introducing subslot-specific priority levels and timeline requirements. The network node determines candidate PUCCH resources based on local subslot conditions, allowing the system to adapt to different service types (eMBB, URLLC, MTC) while maintaining a relatively simple determination procedure

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS20220295479A1Resolving physical uplink control channel collisions in subslots

Publication Date: 2022.09.15 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method, network node and wireless device for resolving physical uplink control channel (PUCCH) collisions in subslots. According to one aspect, a wireless device (WD) is configured to remove a candidate physical uplink control channel, PUCCH, resource from a subslot to resolve an overlap of PUCCH resources in a slot. According to another aspect, a network node is configured to receive a physical uplink control channel, PUCCH, transmission, a PUCCH resource used for the PUCCH transmission being based at least in part on a removal of a candidate PUCCH resource from a subslot to resolve an overlap of PUCCH resources in a slot.