CSI Matrix Decomposition for Wireless Feedback Overhead Reduction

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Solution Overview

Problem

In wireless communications, the feedback of raw channel state information (CSI) between a transmitter and a receiver consumes significant communication resources, particularly in multiple-input and multiple-output (MIMO) technology, due to the large data size and frequent updates required, which can strain the network.

Innovation Solution

A method is introduced to compress the CSI by decomposing the CSI matrix into a vector with significant numbers, generating a shorter vector using a linear operator, and sending this compressed information along with the significant numbers, allowing the transmitter to compute optimal precoders and transmission parameters while reducing feedback overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If raw channel state information (CSI) is fed back from receiver to transmitter, then the transmitter can compute optimal precoders and transmission parameters, but the feedback overhead and communication resource consumption increase significantly

Engineering Contradiction:
ImproveCSI accuracyVSAvoidfeedback data size
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts only the most significant components from the full CSI matrix. The receiver identifies and feeds back only the dominant eigenvectors and eigenvalues that capture the essential channel characteristics, discarding redundant information. This extraction approach maintains precoding accuracy while dramatically reducing feedback overhead from thousands of CSI elements to just a few critical components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms the CSI representation by changing from transmitting the complete CSI matrix to transmitting a compressed set of parameters (eigenvectors and eigenvalues). This parameter transformation allows the same channel information to be conveyed with far fewer bits, reducing feedback overhead while preserving the necessary information for optimal precoder selection.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If complete CSI matrix is transmitted, then full channel information is available at transmitter, but the computational load and processing complexity increase

Engineering Contradiction:
Improvechannel information completenessVSAvoidcomputational load
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts only the essential components (eigenvectors and eigenvalues) from the complete CSI matrix that are necessary for computing optimal precoders. By removing redundant information, the computational complexity at both transmitter and receiver is reduced while maintaining the reliability needed for accurate channel adaptation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the CSI feedback into distinct components: eigenvectors representing spatial directions and eigenvalues representing signal strengths. This segmentation allows the transmitter to process only the necessary components for precoder computation, reducing overall computational load while maintaining complete channel information availability.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If frequent CSI updates are performed, then the system adapts to changing channel conditions, but the network resources and energy consumption increase

Engineering Contradiction:
Improvechannel adaptation speedVSAvoidenergy consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts only the critical channel state components that change with channel conditions and feeds back only these essential parameters. This approach enables frequent CSI updates to track channel variations while consuming less energy than transmitting complete CSI matrices, as the extracted components require fewer bits to transmit and process.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS20240348306A1Method and apparatus for channel state information reporting
Publication Date: 2024.10.17 MEDIATEK SINGAPORE PTE LTD
  • US20240348306A1 patent drawing
  • US20240348306A1 patent drawing
  • US20240348306A1 patent drawing

AI summary

Aspects of the disclosure provide a method, an apparatus, and a non-transitory computer-readable medium for compressing channel state information (CSI). Under the method, a CSI matrix is decomposed, at a first device, into a first vector including a plurality of significant numbers extracted from the CSI matrix. A second vector is generated by multiplying the first vector with a linear operator. A length of the second vector is less than a length of the first vector. The second vector is sent from the first device to a second device along with a number of the plurality of significant numbers in the first vector. The method is implemented in software instructions, and when processing circuitry of the apparatus executes the software instructions, the processing circuitry of the apparatus performs the method. The software instructions are stored in the non-transitory computer-readable medium.