PUCCH Resource Allocation for TDD HARQ-ACK Collision Avoidance

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Solution Overview

Problem

In wireless communication systems, particularly in Time Division Duplex (TDD) mode, there is a challenge in transmitting reception responses when the usage of an uplink subframe is changed to a downlink subframe, leading to potential resource collisions.

Innovation Solution

A method for transmitting an uplink Hybrid ARQ ACKnowledgement (HARQ-ACK) in a wireless communication system, where the User Equipment (UE) employs specific resource allocation strategies to avoid collisions by using different PUCCH resource indices for different downlink subframes within a single uplink subframe, leveraging techniques such as HARQ Resource Offset (ARO) and explicit PUCCH resource mapping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an uplink subframe is changed to a downlink subframe in TDD mode, then the downlink transmission capacity is improved, but resource collision occurs for reception responses

Engineering Contradiction:
Improvedownlink transmission capacityVSAvoidreception response transmission
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the reception response resources by introducing different PUCCH resource indices for different downlink subframes. When multiple downlink subframes are mapped to a single uplink subframe, each downlink subframe is assigned a unique PUCCH resource index, thereby segmenting the resource allocation and avoiding collisions while maintaining the dynamic TDD configuration benefits

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension for resource allocation by using PUCCH resource indices as an additional differentiation parameter. Instead of relying solely on time-domain separation, the invention adds the resource index dimension to distinguish between reception responses from different downlink subframes, enabling collision-free multiplexing

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If multiple downlink subframes are mapped to a single uplink subframe, then the HARQ feedback efficiency is improved, but resource collision occurs for reception responses

Engineering Contradiction:
ImproveHARQ feedback efficiencyVSAvoidresource allocation management
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-configuring multiple PUCCH resource indices corresponding to different downlink subframes before the actual transmission occurs. This pre-configuration allows the UE to systematically select the appropriate resource index based on which downlink subframe the reception response corresponds to, simplifying the resource allocation management while maintaining high HARQ feedback efficiency

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2945310B1Method and apparatus for transmitting receipt confirmation reply in wireless communication system
Publication Date: 2021.09.01 LG ELECTRONICS INC
  • EP2945310B1 patent drawingFigure 1(a)~1(b)
  • EP2945310B1 patent drawingFigure 2
  • EP2945310B1 patent drawingFigure 3~4

AI summary

One embodiment of the present invention relates to a method for user equipment transmitting an uplink receipt confirmation reply in a wireless communication system, comprising the steps of: receiving a downlink signal from subframe n; and transmitting a receipt confirmation reply with respect to the downlink signal from the kth subframe from the subframe from which the downlink signal is received, wherein resource for the receipt confirmation reply from the kth subframe is allocated with priority for subframes in a first group common to downlink subframes required to transmit the receipt confirmation reply from the kth subframe according to a first timeline, and downlink subframes required to transmit the receipt confirmation reply from the kth subframe according to a second timeline.