Multi-TRP Uplink Signaling with Shared Rank Control

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Solution Overview

Problem

Existing wireless communication systems, particularly in new radio (NR), do not support efficient codebook-based uplink transmission for multiple transmission reception points (TRPs), leading to increased downlink control information (DCI) overhead and inefficiencies in uplink transmission.

Innovation Solution

A method and apparatus for transmitting an uplink signal to multiple TRPs using a user equipment (UE) with multiple antennas/panels, where downlink control indicators (DCIs) are utilized to determine transmission rank indicators and transmit precoder matrix indicators for each TRP, reducing DCI overhead and optimizing uplink resource allocation based on radio channel state and UE capability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If codebook-based uplink transmission is supported for multiple TRPs, then uplink transmission reliability and capacity are improved, but DCI overhead and signaling payload increase

Engineering Contradiction:
Improveuplink transmission reliabilityVSAvoidDCI overhead
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent segments the DCI structure by introducing separate fields for multiple TRPs: a first DCI field for first TRP indication information and a second DCI field for second TRP indication information. This segmentation allows independent control and optimization of signaling for each TRP, reducing overall overhead while maintaining multi-TRP transmission capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension of TRP identification by adding TRP indication fields to the DCI structure. This dimensional expansion enables the system to distinguish and address multiple TRPs separately, allowing efficient resource allocation and reduced overhead through targeted signaling rather than blanket multi-TRP commands

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If signaling payload is increased to support multiple TRPs, then uplink transmission capability is improved, but system efficiency deteriorates

Engineering Contradiction:
Improveuplink transmission capabilityVSAvoidsystem efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent changes key parameters of the DCI structure by introducing new fields (first TRP indication field, second TRP indication field) and modifying existing fields (SRI field, TPMI field, rank indication field) to support multi-TRP operations. These parameter changes enable adaptable uplink transmission capability while optimizing signaling efficiency through targeted field design

Inventive Principle:
Principle #35Parameter changes

3Productivity

If DCI overhead is reduced through optimized signaling, then system efficiency is improved, but transmission precision for multiple TRPs may deteriorate

Engineering Contradiction:
Improvesystem efficiencyVSAvoidTRP identification precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent introduces TRP indication information as an intermediary element that mediates between the DCI and multiple TRPs. This intermediary carries precise identification information for each TRP, ensuring accurate TRP selection and resource allocation while maintaining optimized signaling overhead through efficient encoding

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4113854B1Method for transmitting and receiving uplink for plurality of trps and device for same
Publication Date: 2025.10.15 LG ELECTRONICS INC
  • EP4113854B1 patent drawingFigure 1
  • EP4113854B1 patent drawingFigure 2
  • EP4113854B1 patent drawingFigure 3

AI summary

The present invention relates to NR communication. A method for a user equipment provided with a plurality of panels or antennas to transmit an uplink signal to a plurality of transmission reception points (TRPs) comprises the steps of: receiving Downlink Control Indicators (DCI) including first to n-th field values; and transmitting identical uplink data to the plurality of TRPs by using the same number of antenna ports on the basis of the DCIs, wherein the first field value among the first to n-th field values may be determined on the basis of a Transmission Rank Indicator (TRI) and a Transmit Precoder Matrix Indicator (TPMI) corresponding to the selected first TRP among the plurality of TRPs, the second to n-th field values may be determined on the basis of second to n-th TPMIs respectively corresponding to the remaining second to n-th TRPs other than the selected first TRP, and the TRIs corresponding to the second to n-th field values may be determined on the basis of the TRI in the first field value.