Supplemental TDD Timing for Inter-Band Carrier Aggregation

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Solution Overview

Problem

Existing communication systems face challenges in efficiently supporting inter-band carrier aggregation with different UL/DL TDD configurations, leading to inefficiencies in resource allocation and HARQ timing, particularly for UEs operating in full-duplex and half-duplex modes.

Innovation Solution

A system and method for scheduling and HARQ timing in carrier aggregation scenarios with different UL/DL configurations, where primary and secondary cells use distinct TDD configurations, with the secondary cell adapting its timing to a supplemental configuration based on full-duplex or half-duplex modes, and implementing muting strategies to manage resource allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If inter-band carrier aggregation with different UL/DL TDD configurations is implemented, then data transmission capabilities and bandwidth are improved, but resource allocation efficiency and HARQ timing coordination deteriorate

Engineering Contradiction:
Improvedata transmission capabilityVSAvoidresource allocation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the TDD configuration management by introducing a supplemental configuration specifically for the secondary cell that is separate from the primary cell's TDD configuration. This allows independent optimization of HARQ timing for each cell while maintaining overall system coordination, thereby managing the complexity of inter-band carrier aggregation with different UL/DL configurations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic HARQ timing adjustment by allowing the supplemental TDD configuration to be adaptively selected based on the full-duplex or half-duplex mode of the UE. This dynamic adaptation enables the system to optimize resource allocation efficiency under different operational conditions while supporting enhanced data transmission capabilities.

Inventive Principle:
Principle #15Dynamics

2Reliability

If supplemental TDD configuration is introduced for secondary cell, then HARQ timing coordination is improved, but device complexity increases

Engineering Contradiction:
ImproveHARQ timing coordinationVSAvoidconfiguration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies partial action by introducing a supplemental TDD configuration only for the secondary cell rather than reconfiguring the entire system. This selective approach improves HARQ timing coordination for the aggregated carriers while minimizing the increase in overall device complexity by limiting the scope of the additional configuration.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The supplemental TDD configuration acts as an intermediary layer between the primary cell's TDD configuration and the secondary cell's requirements. It mediates the timing coordination by providing a reference framework that enables efficient HARQ timing management without requiring complete system reconfiguration.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If muting strategies are implemented for half-duplex UEs, then resource allocation efficiency is improved, but transmission time is increased

Engineering Contradiction:
Improveresource allocation efficiencyVSAvoidtransmission time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent implements periodic muting strategies where the secondary cell is muted during specific uplink subframes of the primary cell. This periodic action pattern allows half-duplex UEs to efficiently allocate resources by transmitting on the primary cell during its uplink subframes while the secondary cell remains silent, thereby improving resource allocation efficiency without requiring continuous transmission on both cells simultaneously.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4030660B1System and method for supporting inter-band carrier aggregation with different UL/DL TDD configurations
Publication Date: 2025.11.05 BLACKBERRY LTD
  • EP4030660B1 patent drawingFigure 1
  • EP4030660B1 patent drawingFigure 2~3
  • EP4030660B1 patent drawingFigure 4~5

AI summary

In some implementations, a method of wireless communications between a wireless communications network and wireless user equipment includes receiving, using a primary Time Division Duplex (TDD) configuration, data on a primary component carrier in a first frequency band. Using a secondary TDD configuration, data on a secondary component carrier is received in a second frequency band different from the first frequency band. A Hybrid Automatic Repeat Request (HARQ) for data received on the secondary component carrier is transmitted using a supplemental TDD configuration. A transmission or retransmission on the secondary component carrier uses a supplemental TDD configuration as well. The supplemental TDD configuration is different from the secondary TDD configuration. Furthermore, an uplink supplemental configuration may be different from a downlink supplemental configuration.