User Terminal DMRS Mapping for Lower Signaling Overhead

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Solution Overview

Problem

The notification of information related to a port assigned to a user terminal and reference-signal arrangement methods in future radio communication systems leads to an increase in signaling overhead.

Innovation Solution

A user terminal and radio communication method that reduces signaling overhead by implementing specific DMRS arrangement methods based on predetermined conditions, such as port numbers, scrambling IDs, and symbol counts, while supporting flexible port assignment and multiplexing methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If all reference-signal arrangement methods are covered in port assignment notification, then comprehensive signal arrangement support is achieved, but signaling overhead increases

Engineering Contradiction:
Improvereference-signal arrangement supportVSAvoidsignaling overhead
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent segments the reference-signal arrangement methods into multiple types (first type, second type, third type) with different mapping patterns. By dividing the comprehensive arrangement methods into specific categories, the system can notify the terminal of only the applicable type rather than all possible types, thereby reducing signaling overhead while maintaining necessary adaptability for different frequency ranges and propagation environments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by notifying the terminal of only the necessary port assignment information and reference-signal arrangement type relevant to the current communication scenario, rather than providing complete information for all possible arrangement methods. This selective notification reduces signaling overhead while ensuring the terminal has sufficient information for proper signal processing.

Inventive Principle:
Principle #16Partial or excessive action

2Adaptability or versatility

If flexible port assignment is implemented across all frequency ranges, then system adaptability is improved, but notification complexity increases

Engineering Contradiction:
Improvefrequency range adaptabilityVSAvoidnotification complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by defining different reference-signal arrangement methods for different frequency ranges (first frequency range, second frequency range, third frequency range). Each frequency range has its own optimized mapping pattern suitable for its propagation characteristics. This localized approach maintains system adaptability across frequencies while simplifying notification complexity, as the terminal only needs to understand the arrangement method applicable to its current operating frequency.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the parameters of reference-signal arrangement (mapping patterns, port assignments) based on frequency range and propagation conditions. By adjusting these parameters according to local requirements rather than using a universal arrangement method, the system achieves frequency-range adaptability while keeping notification complexity manageable through standardized parameter sets for each frequency category.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4236226B1User terminal
Publication Date: 2026.04.22 NTT DOCOMO INC
  • EP4236226B1 patent drawingFigure 1
  • EP4236226B1 patent drawingFigure 2
  • EP4236226B1 patent drawingFigure 3

AI summary

User terminal (20) receives control information indicating one of possible combination patterns of a plurality of parameters related to arrangement of a demodulation reference signal on a radio resource; and controls reception processing of a downlink signal transmitted by a radio base station based on information indicating that frequency multiplexing between a data signal and the demodulation reference signal is accepted and based on the received control information, the information indicating the acceptance of the frequency multiplexing by a combination pattern of the possible combination patterns which includes at least one of the plurality of parameters configured to a specific value.