Wireless Feedback Information Transmission Using Compressed Sensing

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Solution Overview

Problem

Current wireless communication systems face challenges in reducing feedback overhead, particularly in next-generation 5G networks, where massive Machine Type Communications and Ultra-Reliable and Low Latency Communications require efficient channel feedback mechanisms to minimize latency and enhance communication capacity.

Innovation Solution

The method employs channel sparsity properties to transmit only dominant elements of the channel matrix, using compressed sensing techniques to reduce feedback overhead by quantizing and selecting sparse channel information, allowing for efficient feedback in both subframe structures and hybrid beamforming scenarios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If all elements of the channel matrix are fed back to the transmitter, then the channel information accuracy is improved, but the feedback overhead increases significantly

Engineering Contradiction:
Improvechannel information accuracyVSAvoidfeedback overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts only the dominant elements from the complete channel matrix for feedback transmission. By identifying and selecting only the significant channel components that contribute most to the channel characteristics, the system achieves accurate channel representation while dramatically reducing the quantity of feedback data that needs to be transmitted.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies local quality by treating different elements of the channel matrix differently based on their significance. Instead of uniformly processing all channel elements, the method identifies dominant elements with higher importance and selects them for feedback, while ignoring or coarsely representing less significant elements, thereby optimizing the feedback quality-to-overhead ratio.

Inventive Principle:
Principle #3Local quality

2Quantity of substance

If compressed sensing techniques are used to reduce feedback overhead, then the feedback overhead is reduced, but the complexity of signal recovery algorithms increases

Engineering Contradiction:
Improvefeedback overheadVSAvoidsignal recovery algorithm complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent performs preliminary action by pre-defining a sparsifying basis and establishing a structured sparsity model before the actual feedback process. This preparation work includes identifying the dominant element selection criteria and setting up the compressed sensing framework in advance, which simplifies the real-time recovery process at the transmitter by providing a predetermined structure for signal reconstruction.

Inventive Principle:
Principle #10Preliminary action

3Quantity of substance

If only dominant elements are selected for feedback, then the feedback overhead is reduced, but the channel information completeness may be compromised

Engineering Contradiction:
Improvefeedback overheadVSAvoidchannel information completeness
Core Design Contradiction:
Quantity of substanceVSLoss of information

Solution Approach 1:

The patent substitutes the mechanical approach of transmitting all channel elements with a mathematical signal processing approach using compressed sensing. Instead of physically transmitting every channel coefficient, the system uses mathematical transformations and sparsity exploitation to represent the complete channel information through a compressed set of dominant elements, enabling accurate reconstruction without direct transmission of all components.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3633873B1Method for transmitting feedback information in wireless communication system and apparatus therefor
Publication Date: 2021.11.24 LG ELECTRONICS INC
  • EP3633873B1 patent drawingFigure 1
  • EP3633873B1 patent drawingFigure 2
  • EP3633873B1 patent drawingFigure 3

AI summary

A method for transmitting feedback information by a terminal may comprise the steps of: multiplying each of a left side and a right side of a matrix, which is related to a channel measured by the terminal, by a transformation matrix, so as to obtain a first matrix; performing a first transformation which transforms elements other than a predetermined number of elements having a larger size among elements of the first matrix to zero, or performing a second transformation which transforms elements other than elements exceeding a threshold value to zero, so as to obtain a second matrix; quantizing the second matrix so as to obtain a third matrix; configuring a vector by selecting a specific portion in the third matrix according to a predetermined pattern; configuring, into bits, an output obtained by multiplying the configured vector by a sensing matrix for compression sensing; and transmitting the output bits to a base station.