UE HARQ-ACK Channel Selection for TDD Carrier Aggregation

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Solution Overview

Problem

Current wireless communication systems face limitations in flexibility and efficiency due to the constraints of existing Time-Division Duplexing (TDD) uplink-downlink configurations, particularly in carrier aggregation scenarios where different configurations for primary and secondary cells lead to challenges in HARQ-ACK reporting and resource allocation.

Innovation Solution

The solution involves determining and signaling distinct TDD UL-DL configurations for primary and secondary cells, enabling channel selection for HARQ-ACK information transmission on PUCCH Format 1b, based on the maximum number of elements in specific sets for each cell, to optimize resource allocation and reporting efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If distinct TDD UL-DL configurations are applied for PCell and SCell to improve communication flexibility and efficiency, then communication flexibility and efficiency are improved, but HARQ-ACK reporting complexity and resource allocation difficulty increase

Engineering Contradiction:
Improvecommunication flexibilityVSAvoidHARQ-ACK reporting complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by dynamically determining the set K for each cell based on its specific TDD UL-DL configuration. The size of set K varies depending on the configuration parameters (e.g., downlink subframe indices), allowing the system to adapt HARQ-ACK reporting requirements to match the actual TDD configuration of each cell while managing complexity through parameter-driven variation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamics by making the HARQ-ACK reporting mechanism adaptive rather than static. The channel selection process dynamically adjusts based on the maximum number of elements in set K across PCell and SCell, allowing the system to respond to different TDD configuration combinations in real-time without requiring fixed, pre-determined reporting procedures.

Inventive Principle:
Principle #15Dynamics

2Productivity

If channel selection is performed based on the maximum number of elements in set K between PCell and SCell to optimize resource allocation, then resource allocation efficiency is improved, but the determination process complexity increases

Engineering Contradiction:
Improveresource allocation efficiencyVSAvoiddetermination process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies universality by creating a unified channel selection mechanism that works for both PCell and SCell with different TDD configurations. The procedure uses the maximum of the two set K sizes to determine PUCCH resources, creating a universal rule that handles all configuration combinations without requiring separate determination processes for each cell type.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent implements preliminary action by pre-determining the set K for each cell based on its TDD UL-DL configuration before HARQ-ACK reporting is needed. This advance preparation of configuration parameters allows the system to efficiently determine resource allocation without complex real-time calculations, reducing the operational complexity of the determination process.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2850871B1Devices for sending and receiving feedback information
Publication Date: 2020.04.29 SHARP KK
  • EP2850871B1 patent drawingFigure 1
  • EP2850871B1 patent drawingFigure 2
  • EP2850871B1 patent drawingFigure 3

AI summary

A User Equipment (UE) for sending information to an evolved Node B (eNB) is described. The UE includes an operations unit configured to determine a Time-Division Duplexing (TDD) uplink-downlink (UL-DL) configuration of a primary cell (PCell) and to determine a TDD UL-DL configuration of a secondary cell (SCell), wherein the TDD UL-DL configuration of the SCell is different from the TDD UL-DL configuration of the PCell and a transmitting unit configured to transmit Hybrid Automatic Repeat Request Acknowledgement/Negative Acknowledgement (HARQ-ACK) information on Physical Uplink Control Channel (PUCCH) Format 1b with channel selection, wherein the channel selection is performed based on a maximum number between the number of elements corresponding to a subframe n in the set K for the PCell and the number of elements corresponding to the subframe n in the set K for the SCell,