Dynamic Cross-Carrier Scheduling for URLLC Latency Reduction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current wireless communication networks face challenges in reducing latency and enhancing reliability for ultra-reliable and low-latency communication (URLLC) due to limitations in cross-carrier scheduling for uplink control information (UCI) transmission, particularly in Time Division Duplex (TDD) systems, which lead to prolonged alignment delays and inhibit efficient retransmissions.

Innovation Solution

Implementing dynamic cross-carrier scheduling mechanisms that allow flexible and dynamic switching of carriers for PUCCH, PDSCH, and PUSCH transmissions, along with enhanced PUCCH formats to reduce latency and improve reliability by configuring multiple carriers with different TDD patterns and utilizing SR resources across multiple cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If cross-carrier scheduling is implemented for PUCCH transmission, then alignment delay is reduced and URLLC latency is improved, but device complexity and scheduling overhead increase

Engineering Contradiction:

Improvealignment delayVSAvoidscheduling complexity

Core Design Contradiction:

Loss of timeVSDevice complexity

Solution Approach 1:

The patent implements dynamic cross-carrier scheduling where the PUCCH carrier can be dynamically switched between different component carriers based on real-time network conditions and TDD patterns. This dynamic selection allows the system to adaptively choose the optimal carrier for PUCCH transmission, reducing alignment delays while managing complexity through configurable dynamic switching mechanisms

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of PUCCH carrier selection from static to dynamic by introducing configurable cross-carrier scheduling parameters. The network can configure multiple PUCCH carriers with different TDD patterns, and the UE can dynamically select among them based on scheduling indications, thereby changing the system behavior from fixed to flexible carrier selection

Inventive Principle:

Principle #35Parameter changes

2Reliability

If multiple PUCCH resources are allocated for HARQ feedback transmission, then transmission reliability is improved, but resource overhead and system complexity increase

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidresource management complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the PUCCH resources across multiple component carriers, allowing HARQ feedback to be transmitted on different carriers. This segmentation provides diversity in case one carrier experiences poor conditions, improving reliability while distributing the resource management burden across multiple independent carriers

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent enables PUCCH resources to serve multiple purposes by allowing the same UE to use different PUCCH carriers for different HARQ feedback transmissions. The multi-carrier PUCCH resources provide universal coverage and redundancy, improving reliability without requiring separate dedicated resources for each transmission

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If TDD pattern is used to divide uplink and downlink slots, then asymmetric traffic support is improved, but PUCCH alignment delay increases when uplink slots are sparse

Engineering Contradiction:

Improveasymmetric traffic supportVSAvoidPUCCH alignment delay

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent adds another dimension to PUCCH transmission by introducing cross-carrier scheduling. Instead of being constrained to the time dimension (waiting for the next uplink slot on the same carrier), the system can switch to a different carrier dimension that may have more favorable TDD patterns, thereby reducing alignment delay while maintaining asymmetric traffic support

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

4Productivity

If cross-carrier scheduling is enabled for PDSCH, then transmission efficiency is improved, but control reliability requirements become stricter

Engineering Contradiction:

Improvetransmission efficiencyVSAvoidcontrol reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent introduces an intermediary mechanism where the PDCCH on one carrier can schedule PDSCH on another carrier, and the PUCCH for HARQ feedback can be transmitted on a third carrier. This intermediary cross-carrier scheduling allows the system to separate control and data transmissions, improving transmission efficiency while providing multiple paths for reliable feedback

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20250212216A1Method and apparatus for dynamic cross-carrier scheduling in mobile communications

Publication Date: 2025.06.26 MEDIATEK SINGAPORE PTE LTD

AI summary

A method for dynamic cross-carrier scheduling with respect to user equipment receiving, by a processor of an apparatus, a physical downlink control channel (PDCCH) on a first component carrier (CC). The method also receiving, by the processor, a physical downlink shared channel (PDSCH) on the first CC scheduled by the PDCCH, and determining, by the processor, a second CC to transmit a physical uplink control channel (PUCCH) according to a configuration of dynamic switching of CC. The method further transmitting, by the processor, the PUCCH corresponding to the PDSCH on the second CC scheduled by the PDCCH, and receiving, by the processor, the PDCCH on second CC. Finally, the method receiving, by the processor, the PDSCH on the second CC scheduled by the PDCCH.