Distance-Partitioned Precoding Codebooks for Near-Field CSI Feedback

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Solution Overview

Problem

The existing 5G standards rely on DFT codebooks that lead to increased feedback errors due to the lack of distance-domain partitioning, degrading communication system transmission performance, especially in near-field scenarios.

Innovation Solution

Implementing a codebook with distance-domain partitioning by using a precoding matrix formed of vectors generated by functions with parameters from candidate sets, ensuring the difference between adjacent elements is distinct, allowing accurate channel state information feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If DFT codebook is employed for CSI feedback, then the codebook structure is simple and easy to implement, but feedback errors increase and transmission performance degrades

Engineering Contradiction:
Improvecodebook implementation simplicityVSAvoidCSI feedback accuracy
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The codebook is segmented into multiple subsets based on distance-domain partitioning. Each subset corresponds to a specific distance range, allowing the system to select the appropriate subset for near-field or far-field scenarios. This segmentation enables the codebook to adapt to different transmission scenarios while maintaining implementation simplicity through structured organization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces distance as a new parameter for codebook selection, changing from traditional angle-only parameterization. By incorporating distance-domain partitioning with multiple candidate sets, the system can adjust codebook parameters based on the actual transmission distance, improving CSI feedback accuracy without significantly complicating the overall implementation.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If distance-domain partitioning is implemented, then CSI feedback accuracy improves, but codebook complexity increases

Engineering Contradiction:
Improvechannel state information feedback accuracyVSAvoidcodebook structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The codebook is divided into multiple distance-based subsets, each containing precoding matrices appropriate for specific distance ranges. This segmentation strategy improves measurement precision by selecting the most suitable precoding matrices for the actual transmission scenario while keeping the overall structure organized and manageable through clear distance-based categorization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent adds distance as an additional dimension to the traditional angle-based codebook parameterization. By introducing distance-domain partitioning alongside angle-domain partitioning, the system achieves more accurate CSI feedback without overwhelming complexity, as the distance parameter provides an intuitive and physically meaningful way to organize codebook entries.

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

3Adaptability or versatility

If DFT codebook is used, then the system is well-suited for far-field scenarios, but performance degrades in near-field scenarios

Engineering Contradiction:
Improvefar-field scenario suitabilityVSAvoidnear-field transmission performance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The codebook system is made dynamic by allowing selection of different codebook subsets based on the transmission distance. For near-field scenarios, the system selects from near-field optimized subsets, while for far-field scenarios, it uses traditional DFT codebook subsets. This dynamic adaptation maintains far-field suitability while improving near-field performance through context-aware codebook selection.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The enhanced codebook structure serves multiple functions by incorporating both near-field and far-field optimized precoding matrices within a single unified codebook framework. The distance-domain partitioning enables the same codebook structure to adapt to different transmission scenarios, providing universal applicability across both near-field and far-field communications.

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

Data Source

PatentEP4597862A1Channel information acquisition method, communication device and storage medium
Publication Date: 2025.08.06 ZTE CORP
  • EP4597862A1 patent drawingFigure 1~3
  • EP4597862A1 patent drawingFigure 4~5
  • EP4597862A1 patent drawing

AI summary

Provided are a channel information acquisition method, a communication device and a storage medium. The channel information acquisition method applied by a first communication node includes: receiving a measurement reference signal; selecting a precoding matrix from a codebook according to the received measurement reference signal, where the precoding matrix is formed of vectors, a vector of the vectors is generated by a function, a first parameter and a second parameter in the function belong to a first candidate set and a second candidate set, respectively, and when elements in the second candidate set are arranged in sequence, the difference between two adjacent elements is different; and reporting the precoding matrix to a second communication node.