Hybrid Automatic Repeat Request Feedback Mapping for TDD Heterogeneous Networks

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Solution Overview

Problem

In LTE release 11, the challenge arises in handling feedback information for cells with different uplink and downlink configurations within a heterogeneous network, where the number of subframes requiring feedback information differs between primary and secondary cells, necessitating a method to efficiently process and send feedback in a unified manner.

Innovation Solution

A method is introduced to determine and send separate indication information for each downlink subframe of primary and secondary cells, using first and second indication information to process and map feedback information accordingly, allowing for different uplink and downlink configurations, ensuring accurate and efficient feedback transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a unified feedback processing method is used for all cells, then the processing complexity is reduced and ease of operation is improved, but the adaptability to handle different uplink and downlink configurations is worsened

Engineering Contradiction:

Improvefeedback processing simplicityVSAvoidconfiguration flexibility

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The feedback processing method is segmented into two distinct paths: one for cells with the same TDD uplink and downlink configuration (using unified channel selection mapping) and another for cells with different configurations (using separate indication information processing). This segmentation allows the system to maintain simplicity where applicable while adapting to diversity where necessary.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically selects the appropriate feedback processing method based on whether cells have the same or different TDD configurations. When configurations are identical, the simpler unified method is used; when they differ, the more flexible separate processing method is activated, optimizing the balance between complexity and adaptability.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If separate processing methods are used for cells with different configurations, then the adaptability is improved, but the device complexity and processing overhead are worsened

Engineering Contradiction:

Improveconfiguration flexibilityVSAvoidfeedback processing complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Different processing qualities are applied locally to different cell groups: cells with the same configuration receive simplified unified processing, while cells with different configurations receive enhanced separate processing. This local differentiation minimizes overall complexity while providing necessary adaptability where required.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The base station and user equipment are designed with multi-functional capability to handle both unified and separate feedback processing methods. This universality allows the system to switch between processing modes based on configuration requirements without requiring separate dedicated systems, thereby controlling complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Productivity

If feedback information from multiple cells is sent in the same uplink subframe, then the transmission efficiency is improved, but the reliability of feedback information distinction is worsened

Engineering Contradiction:

Improvefeedback transmission efficiencyVSAvoidfeedback information accuracy

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Separate indication information acts as an intermediary layer between the feedback information from different cells and the unified uplink transmission. This intermediary clearly identifies which feedback information belongs to which cell, maintaining reliability while enabling efficient combined transmission in the same uplink subframe.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Different indication information types serve as distinct identifiers (analogous to color coding) for feedback information from different cells. This clear differentiation ensures that even when multiple feedback streams are combined in the same uplink subframe, the base station can reliably distinguish and process each cell's feedback information separately.

Inventive Principle:

Principle #32Color changes

Data Source

PatentUS10298351B2Method for implementing hybrid automatic repeat request, user equipment, and base station

Publication Date: 2019.05.21 HUAWEI DEVICE CO LTD

AI summary

Embodiments of the present invention provide a method for implementing hybrid automatic repeat request, a user equipment, and a base station. The method includes: determining first indication information and second indication information separately according to feedback information of each downlink subframe of a primary cell and that of a secondary cell that need to be sent in a same uplink subframe of the primary cell, where the first indication information is used to indicate first feedback information of each downlink subframe of the primary cell that needs to be sent in the uplink subframe, and the second indication information is used to indicate second feedback information of each downlink subframe of the secondary cell that needs to be sent in the uplink subframe; sending mapping information of the first indication information and the second indication information in the uplink subframe.