Dynamic TDD Uplink Feedback Resource Allocation

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Solution Overview

Problem

In dynamic TDD systems, the existing uplink-downlink configuration schemes face challenges in managing real-time service changes and user equipment compatibility, leading to potential ACK/NACK resource conflicts between users with different releases, especially in PDSCH with PDCCH scheduling or PDCCH indicating SPS resource releasing scenarios.

Innovation Solution

The method involves determining ACK/NACK resources based on dynamic sub-frame configurations, using a set of sub-frames that include both static and flexible allocations, where resources for users with different releases are managed by employing distinct schemes for each set of sub-frames, ensuring compatibility and avoiding resource conflicts through higher layer signaling and predefined configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a new HARQ scheme is used for dynamic TDD systems to accommodate flexible uplink-downlink sub-frame configuration, then adaptability to dynamic service demands is improved, but PUCCH resource confliction occurs between users of different releases

Engineering Contradiction:
Improveadaptability to dynamic service demandsVSAvoidPUCCH resource confliction
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the sub-frame configuration into two distinct sets: a first set for which a first HARQ scheme is used, and a second set for which a second HARQ scheme is used. This segmentation allows different HARQ schemes to coexist without resource confliction, as each set is handled by its dedicated scheme. The segmentation resolves the contradiction by enabling adaptability through multiple schemes while preventing reliability issues through isolated resource management.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary mechanism in the form of higher layer signaling that configures the mapping between downlink sub-frames and uplink feedback sub-frames for the first HARQ scheme. This intermediary layer mediates between the dynamic TDD requirements and the legacy user equipment, allowing flexible configuration while maintaining compatibility and avoiding resource confliction with existing schemes.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If existing PUCCH format 1/1a/1b resource index mapping method is used for backward compatibility, then compatibility with lower release users is maintained, but PUCCH resource confliction occurs between R11 and later users and lower release users

Engineering Contradiction:
Improvebackward compatibilityVSAvoidPUCCH resource confliction
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments user equipment into two categories: users of R11 and later releases that use the first HARQ scheme, and users of lower releases that use the second HARQ scheme. Each segment is assigned dedicated PUCCH resources through distinct mapping methods, preventing resource confliction while maintaining backward compatibility. Lower release users continue to use the existing mapping method without interference, while newer users benefit from enhanced flexibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different resource mapping qualities to different user groups: the first HARQ scheme uses a configured mapping method optimized for dynamic TDD, while the second HARQ scheme uses the traditional mapping method optimized for legacy systems. This local quality differentiation ensures that each user group receives the appropriate resource allocation strategy, avoiding confliction while preserving compatibility.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If online change to proportion of uplink-downlink timeslots is implemented to trace real-time service changes, then adaptability to service demands is improved, but signaling flow complexity and configuration time increase, lowering system performance

Engineering Contradiction:
Improvereal-time service change trackingVSAvoidsignaling flow complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary configuration of HARQ schemes and PUCCH resource mappings through higher layer signaling before dynamic sub-frame allocation occurs. By pre-configuring the mapping relationships and resource allocations, the system enables real-time adaptability without requiring complex online reconfiguration signaling. The preliminary setup establishes the framework that allows flexible sub-frame assignment while maintaining low signaling overhead during operation.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2744139B1Uplink feedback method and apparatus
Publication Date: 2017.09.13 CHINA ACAD OF TELECOMM TECH
  • EP2744139B1 patent drawingFigure 1~2
  • EP2744139B1 patent drawingFigure 3~4
  • EP2744139B1 patent drawingFigure 5a~5b

AI summary

There are disclosed a method of and system and apparatus for performing an uplink feedback, applicable to a dynamic sub-frame system, so as to avoid collision of ACK/NACK resources between a non-dynamic system and a dynamic system from occurring. The method includes: determining ACK/NACK resource for carrying ACK/NACK, corresponding to downlink data in a sub-frame n according to a set of sub-frames including a sub-frame in which the downlink data is received; and transmitting ACK/NACK information corresponding to the downlink data over the ACK/NACK resource in the sub-frame n, wherein the set of sub-frames includes a first set of sub-frames and/or a second set of sub-frames; the set of sub-frames is determined by obtained uplink/downlink sub-frame configuration information and flexible sub-frame information; the uplink/downlink sub-frame configuration information indicates the type of each sub-frame in a radio frame as an uplink sub-frame, a downlink sub-frame and a special sub-frame; and the flexible sub-frame information indicates the type of each sub-frame in a radio frame as an uplink sub-frame, a downlink sub-frame, a special sub-frame and a flexible sub-frame, wherein the flexible sub-frame can be used for transmission of uplink or downlink data.