HARQ Codebook Indexing for Multi-Cell DCI Scheduling

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Solution Overview

Problem

Existing methods struggle to determine enhanced Type-3 HARQ codebook indices in multi-cell scheduling scenarios, as the existing single-cell scheduling indication fields for DCI format 1_X are inadequate for multi-cell scenarios.

Innovation Solution

A method for determining enhanced Type-3 HARQ codebook indices involves receiving DCI from a base station, identifying a reference cell within a target cell set, and using target information indicators such as FDRA and MCS indicators to determine the enhanced Type-3 HARQ codebook indices, even in the absence of explicit indicators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If single-cell scheduling indication fields are used for DCI format 1_X, then the indication is simple and clear, but it cannot be directly applied to multi-cell scheduling scenarios

Engineering Contradiction:
Improvemulti-cell scheduling compatibilityVSAvoidindication field structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the existing single-cell scheduling indication fields serve multiple functions by reinterpreting them for multi-cell scenarios. Specifically, the FDRA and MCS indicators that originally indicated resources and modulation for a single cell are repurposed to indicate codebook indices for multiple cells, allowing the same field structure to support both single-cell and multi-cell scheduling without adding new dedicated fields.

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

Solution Approach 2:

The patent changes the interpretation of existing parameters rather than creating new ones. The FDRA indicator values and MCS indicator values are reinterpreted to represent codebook index information for multiple cells instead of traditional resource allocation parameters. This parameter reinterpretation allows the same indication fields to convey different types of information depending on the scheduling scenario.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If enhanced Type-3 codebook indices are indicated by MCS information indicator in single-cell scheduling, then the indication is efficient, but it is inadequate for multi-cell scheduling where multiple cells need to be scheduled

Engineering Contradiction:
Improvecodebook indication efficiencyVSAvoidcodebook index information completeness
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent merges the functionality of multiple indication fields to convey codebook index information for multiple cells. By combining the information from FDRA indicators and MCS indicators across multiple cells, the system can indicate codebook indices for all scheduled cells using the existing field structure, thereby maintaining indication efficiency while providing complete codebook information for multi-cell scenarios.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The FDRA and MCS indicator fields are given multi-functional roles: in single-cell scheduling they indicate traditional resource allocation parameters, while in multi-cell scheduling they indicate codebook indices for multiple cells. This universal application of existing fields eliminates the need for separate dedicated fields for codebook indication in multi-cell scenarios.

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

3Measurement precision

If a reference cell is determined from target cell set using FDRA and MCS indicators, then codebook index determination is accurate, but the method complexity increases compared to direct indication

Engineering Contradiction:
Improvecodebook index determination accuracyVSAvoidindex determination process
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent enables the terminal to self-determine the reference cell and codebook indices using the existing FDRA and MCS indicator values already present in the DCI. Instead of requiring the base station to explicitly indicate which cell is the reference cell or what the codebook indices are, the terminal autonomously derives this information from the scheduling indicators intended for other purposes, simplifying the overall indication mechanism while maintaining accuracy.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the interpretation of FDRA and MCS parameter values from traditional resource allocation meanings to codebook index identification meanings. By reinterpreting these parameters in the context of multi-cell scheduling, the system can accurately determine codebook indices without requiring additional explicit indication fields or complex reference cell identification mechanisms.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4712381A1Method and apparatus for determining enhanced type-3 HARQ codebook index, and terminal and base station
Publication Date: 2026.03.18 DATANG MOBILE COMM EQUIP CO LTD
  • EP4712381A1 patent drawingFigure 1~3
  • EP4712381A1 patent drawingFigure 4~6
  • EP4712381A1 patent drawing

AI summary

The present disclosure provides methods, apparatuses, terminals and base stations for determining one or more enhanced Type-3 HARQ codebook indices, belonging to the field of communications technology. The method includes: receiving a first DCI sent by a base station, the first DCI being used for scheduling at least one downlink cell in a target cell set; determining at least one reference cell from the target cell set; and determining one or more enhanced Type-3 HARQ codebook indices according to one or more target information indicators of the reference cell in the first DCI.