CSI Codeword Compression for Lower MIMO Reporting Overhead

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Solution Overview

Problem

The high information overheads associated with CSI reporting in mobile communication systems, particularly in MIMO technologies, necessitate a reduction to enhance efficiency.

Innovation Solution

A method and apparatus for CSI reporting that involves generating and feeding back codewords based on coefficient matrices and dictionary matrices to reduce information overheads, utilizing specific matrix products and periodicity strategies for efficient compression and transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the quantity of antennas used by a base station to send a signal increases to improve MIMO technology performance, then the signal transmission quality and system capacity are improved, but the information overheads in CSI reporting increase

Engineering Contradiction:
Improvesignal transmission qualityVSAvoidinformation overheads in CSI reporting
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent segments the CSI reporting process into two parts: a first codeword containing compressed channel state information and a second codeword containing precoding matrix information. This segmentation allows independent optimization of each codeword's compression ratio and reporting format, reducing overall information overhead while maintaining the benefits of increased antenna quantities for MIMO transmission

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts and reports only the most significant components of the channel state information rather than the complete CSI data set. By identifying and reporting key parameters that capture the essential channel characteristics, the system reduces information overhead in CSI reporting while still supporting high-performance MIMO operations with increased antenna quantities

Inventive Principle:
Principle #2Taking out (Extraction)

2Loss of information

If dual-domain compression is used for CSI reporting, then the information overheads are reduced, but the complexity of the reporting mechanism increases

Engineering Contradiction:
Improveinformation overheads in CSI reportingVSAvoidcomplexity of CSI reporting mechanism
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent applies different compression strategies to different domains of CSI information. In the spatial domain, it uses specific codebook-based compression, while in the frequency domain, it employs subband-based compression. This localized approach to compression allows optimization for each domain's characteristics, reducing overall information overhead without requiring a single complex universal compression mechanism

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces dynamic selection of reporting configurations, where the terminal can adaptively choose between different codeword formats and compression levels based on channel conditions and network requirements. This dynamic approach allows the system to balance compression efficiency against processing complexity in real-time, reducing information overhead without permanently increasing mechanism complexity

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4092919B1Method and apparatus for transmitting information
Publication Date: 2025.09.03 HUAWEI TECH CO LTD
  • EP4092919B1 patent drawingFigure 1
  • EP4092919B1 patent drawingFigure 2~3
  • EP4092919B1 patent drawingFigure 4

AI summary

An information transmission method and apparatus are provided. In the method, a terminal device generates a first codeword, where the first codeword is obtained based on a second codeword, a quantity of elements included in the second codeword is greater than a quantity of elements included in the first codeword, the second codeword is associated with a first coefficient set of a downlink channel, and the first coefficient set includes an element included in at least one row vector or column vector of a first coefficient matrix; and then the terminal device feeds back the first codeword to a network device. The terminal device can indicate a position and a numerical value of an element in the first coefficient set by reporting only the first codeword. This manner is simple. In addition, a codeword length of the first codeword is shorter than a codeword length of the second codeword. Therefore, a quantity of bits required for reporting the first codeword by the terminal device is definitely less than a quantity of bits occupied for reporting at least one space-frequency combination coefficient, reducing overheads.