Two-Stage 4×4 Hermitian EVD for Wireless Signal Analysis

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Solution Overview

Problem

Performing eigenvalue decomposition (EVD) on a four by four Hermitian matrix in wireless communication systems is computationally complex and can lead to inaccurate results.

Innovation Solution

A two-stage decomposition method is employed, where a four by four Hermitian matrix is first transformed into a three by three Hermitian matrix through a diagonal shift, followed by QR decomposition and a closed-form solution to determine eigenvalues and eigenvectors, reducing computational complexity and improving accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If eigenvalue decomposition is performed on a four by four Hermitian matrix using conventional methods, then the decomposition can be completed, but the computational complexity is high and results may be inaccurate

Engineering Contradiction:
Improveaccuracy of EVD resultsVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the four by four Hermitian matrix decomposition problem into two stages: first performing decomposition on a reduced three by three Hermitian matrix, then using the results to obtain the decomposition of the original four by four matrix. This segmentation reduces computational complexity while maintaining accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary three by three Hermitian matrix as a mediator between the original signal and the final decomposition results. By decomposing this intermediate matrix first, the computational burden is reduced while the results can be transformed back to obtain the decomposition of the original four by four matrix.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If eigenvalue decomposition is performed on a four by four Hermitian matrix, then the decomposition results are obtained, but the processing time increases due to computational complexity

Engineering Contradiction:
Improveprocessing speedVSAvoidcomputational complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the EVD process into segmented stages, processing a three by three matrix first and then deriving the four by four results. This segmentation enables faster processing by reducing the initial computational burden while maintaining complete decomposition results.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary decomposition on the three by three Hermitian matrix before addressing the full four by four matrix. This preliminary action reduces the overall computational complexity and processing time required for the complete decomposition task.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS12432100B2Performing a two-stage decomposition on a four by four Hermitian matrix associated with a wireless communication signal analysis
Publication Date: 2025.09.30 QUALCOMM INC
  • US12432100B2 patent drawing
  • US12432100B2 patent drawing
  • US12432100B2 patent drawing

AI summary

Various aspects of the present disclosure generally relate to wireless communication. Various aspects relate generally to determining information metrics associated with an eigenvalue decomposition (EVD) operation associated with a four by four Hermitian matrix. Some aspects more specifically relate to determining a scalar (e.g., an eigenvalue or an approximation of an eigenvalue) of the four by four Hermitian matrix and determining a shifted matrix by subtracting a product of the scalar and an identity matrix from the four by four Hermitian matrix. A QR decomposition may be performed on the shifted matrix to determine first derived information, representable by a three by three Hermitian matrix. An eigenvalue decomposition operation may be performed on the three by three Hermitian matrix to determine the eigenvalues and eigenvectors of the four by four Hermitian matrix.