Precoding Matrix Configuration for DMRS Port Mapping in Wireless Systems

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Solution Overview

Problem

Legacy CDD methods in evolved antenna systems face reduced CDD gain due to limitations in DMRS port management and precoding matrix configuration, which affects signal transmission efficiency in wireless communication systems.

Innovation Solution

A method involving the sequential application of a unit matrix U, a diagonal matrix D, and a precoding matrix W to complex modulation symbols, allowing for flexible mapping of DMRS ports and precoder sets, including the use of identical column vectors and orthogonal column vectors, to optimize DMRS port configuration and prevent CDD gain reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If legacy CDD methods are used in evolved antenna systems, then signal transmission is supported, but CDD gain is reduced due to limitations in DMRS port management and precoding matrix configuration

Engineering Contradiction:
ImproveCDD gainVSAvoidDMRS port management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the parameters of precoding matrix configuration by allowing flexible mapping between DMRS ports and precoder sets. Specifically, when the number of DMRS ports is less than M*L, the precoder sets include identical column vectors that can be positioned at different columns, and column vectors can be orthogonal to each other. This parameter adjustment optimizes the relationship between reference signals and data transmission, preventing CDD gain reduction while adapting to evolved antenna systems.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the number of DMRS ports is less than M*L, then resource efficiency is improved, but precoding matrix configuration becomes more complex

Engineering Contradiction:
Improveresource efficiencyVSAvoidprecoding matrix configuration
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies universality by designing precoder sets where identical column vectors can serve multiple DMRS ports. When the number of DMRS ports is less than M*L, the same column vector from the precoder sets can be reused across different DMRS ports, allowing a single precoding configuration to serve multiple reference signal ports. This multi-functional approach improves resource efficiency while managing configuration complexity through standardized vector reuse.

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

Solution Approach 2:

The patent segments the precoding matrix into M number of precoder sets, each containing multiple column vectors. This segmentation allows flexible selection and combination of column vectors for different DMRS ports. When DMRS ports are fewer than M*L, the segmented structure enables selective reuse of identical column vectors across different precoder sets, optimizing resource usage while maintaining manageable configuration through modular organization.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If identical column vectors are used in precoder sets, then DMRS port mapping flexibility is improved, but orthogonality between different DMRS ports may be affected

Engineering Contradiction:
ImproveDMRS port mapping flexibilityVSAvoidorthogonality between DMRS ports
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies local quality by allowing identical column vectors to be positioned at different columns within the precoder sets for different DMRS ports. This means that while the same vector pattern is used (providing flexibility), its position varies locally for each DMRS port configuration. Additionally, the patent ensures that column vectors within the same precoder set maintain orthogonality relationships, thus preserving signal separation quality locally while achieving global mapping flexibility through the structured reuse of identical vectors across different ports.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3217568B1Signal transmission method and apparatus of apparatus having plurality of antennas in wireless communication system
Publication Date: 2020.12.30 LG ELECTRONICS INC
  • EP3217568B1 patent drawingFigure 1(a)~1(b)
  • EP3217568B1 patent drawingFigure 2
  • EP3217568B1 patent drawingFigure 3~4

AI summary

A method for transmitting a signal by an apparatus having a plurality of antennas in a wireless communication system, according to one embodiment of the present invention, comprises the steps of: mapping complex modulation symbols to L layers; sequentially applying a unit matrix U, a diagonal matrix D, and a precoding matrix W to the symbols which have been mapped to the L layers; and mapping symbols which have been mapped to DMRS ports by applying W, D and U, wherein W is one of M sets of precoders, each of the M sets of precoders comprising a plurality of column vectors, and wherein if the number of DMRS ports is smaller than M * L, the M sets of precoders include at least one identical column vector.