HARQ Timeline Remapping in TDD UL-DL Reconfiguration

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Solution Overview

Problem

HARQ timeline mismatches occur in LTE TDD systems due to dynamic switching among different TDD UL-DL configurations, affecting transmission performance and degrading achievable performance gains from traffic adaptation.

Innovation Solution

A method for remapping HARQ timeline by determining a TDD UL-DL reference configuration based on UL subframe allocations, allowing HARQ processes to follow the timeline of this reference configuration during TDD UL-DL reconfiguration, ensuring seamless transition and avoiding mismatches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If dynamic switching among different TDD UL-DL configurations is performed for traffic adaptation, then average cell throughput is improved, but HARQ timeline mismatch occurs causing transmission performance degradation

Engineering Contradiction:

Improveaverage cell throughputVSAvoidtransmission performance

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent introduces a reference configuration as an intermediary element that mediates between the source configuration and target configuration during TDD reconfiguration. This reference configuration serves as a temporary HARQ timeline reference that ensures continuous and mismatch-free HARQ operations during the transition period, resolving the contradiction between dynamic adaptability and transmission reliability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent determines a reference configuration in advance before the actual TDD reconfiguration occurs. This preliminary action of establishing the reference configuration ensures that the HARQ timeline is pre-prepared and ready to prevent mismatches during the transition, allowing seamless switching between configurations without degrading transmission performance.

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If TDD UL-DL reconfiguration is performed for traffic adaptation, then system adaptability is improved, but HARQ timeline interruptions occur

Engineering Contradiction:

Improvetraffic adaptation capabilityVSAvoidHARQ timeline continuity

Core Design Contradiction:

Adaptability or versatilityVSDuration of action of stationary object

Solution Approach 1:

The reference configuration acts as an intermediary that bridges the source and target TDD configurations during reconfiguration. By using this intermediate reference, the system maintains continuous HARQ timeline without interruptions while still achieving the desired traffic adaptation through configuration switching.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent ensures continuous HARQ operations during TDD reconfiguration by having the UE perform HARQ processes according to the reference configuration's timeline. This continuity principle prevents HARQ timeline interruptions while allowing the system to adapt to different traffic conditions through configuration changes.

Inventive Principle:

Principle #20Continuity of useful action

3Reliability

If HARQ timeline is strictly followed for each TDD configuration, then transmission reliability is maintained, but flexibility in configuration switching is reduced

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidconfiguration switching flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic HARQ timeline management where the timeline is adapted based on the reference configuration rather than being rigidly tied to each individual TDD configuration. This dynamic approach allows flexible configuration switching while maintaining transmission reliability through the reference configuration's HARQ timeline.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The reference configuration serves multiple functions: it acts as a HARQ timeline reference during transitions, enables flexible configuration switching, and maintains transmission reliability. This universal element allows the system to achieve both reliability and adaptability simultaneously by serving multiple purposes.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS9496990B2Method of remapping hybrid automatic repeat request timeline in time division duplex uplink-downlink reconfiguration

Publication Date: 2016.11.15 HTC CORP

AI summary

A method of remapping Hybrid Automatic Repeat Request (HARQ) timeline in Time Division Duplex (TDD) uplink-downlink (UL-DL) reconfiguration, for a communication device in a wireless communication system is disclosed. The method includes being reconfigured from a first TDD UL-DL configuration in a first radio frame to a second TDD UL-DL configuration in a second radio frame, determining a TDD UL-DL reference configuration according to UL subframe allocations of the first and second TDD UL-DL configurations in the first radio frame, and performing HARQ processes of the first TDD UL-DL configuration according to a HARQ timeline of the TDD UL-DL reference configuration during the first and second radio frames.