NR User Terminal DMRS Power Allocation for Stable Shared-Channel Transmission

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Solution Overview

Problem

In future radio communication systems like NR, the use of different transmission powers for data symbols and DMRS symbols can cause interference and reduce throughput due to fluctuations in the signal waveform when power switching occurs.

Innovation Solution

A user terminal is designed to use the same transmission power for both data and DMRS symbols by determining DMRS power without considering unallocated resource elements, referencing a table that defines the power ratio for each resource element, ensuring consistent power allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a user terminal performs measurements and communications in both first and second frequency bands simultaneously, then measurement accuracy and communication capability are improved, but power consumption increases and measurement accuracy in the first frequency band deteriorates due to interference

Engineering Contradiction:
Improvefrequency band adaptabilityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent implements dynamic operation modes that can switch between simultaneous dual-band operation and sequential operation. The controller dynamically selects the appropriate mode based on current needs, and within sequential mode, dynamically adjusts timing parameters to optimize performance while reducing interference and power consumption compared to continuous simultaneous operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs periodic action by implementing sequential measurement and communication operations in time-divided intervals. The first measurement unit operates during a first time period, then the second communication unit operates during a second time period, creating a periodic cycle that reduces continuous power consumption and eliminates simultaneous interference while maintaining both functionalities over time.

Inventive Principle:
Principle #19Periodic action

2Measurement precision

If a user terminal performs measurements and communications in both first and second frequency bands simultaneously, then measurement accuracy and communication capability are improved, but measurement accuracy in the first frequency band deteriorates due to interference

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidinterference
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent employs periodic action by implementing sequential measurement and communication operations in time-divided intervals. The first measurement unit operates during a first time period, then the second communication unit operates during a second time period, creating a periodic cycle that reduces continuous power consumption and eliminates simultaneous interference while maintaining both functionalities over time.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent segments the operation into distinct time periods and functional units. The measurement function is segmented into a first measurement unit operating in a first time period, and the communication function is segmented into a second communication unit operating in a second time period. This temporal segmentation eliminates interference between functions while maintaining both capabilities.

Inventive Principle:
Principle #1Segmentation

3Productivity

If a user terminal performs measurements and communications in both first and second frequency bands simultaneously, then communication capability is improved, but measurement accuracy deteriorates due to interference

Engineering Contradiction:
Improvecommunication capabilityVSAvoidmeasurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent employs periodic action by implementing sequential measurement and communication operations in time-divided intervals. The first measurement unit operates during a first time period, then the second communication unit operates during a second time period, creating a periodic cycle that reduces continuous power consumption and eliminates simultaneous interference while maintaining both functionalities over time.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent implements dynamic operation modes that can switch between simultaneous dual-band operation and sequential operation. The controller dynamically selects the appropriate mode based on current needs, and within sequential mode, dynamically adjusts timing parameters to optimize performance while reducing interference and power consumption compared to continuous simultaneous operation.

Inventive Principle:
Principle #15Dynamics

4Adaptability or versatility

If a user terminal performs measurements and communications in both first and second frequency bands simultaneously, then measurement and communication functions are maintained, but device complexity increases

Engineering Contradiction:
Improvedual frequency band operationVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements multi-functionality by designing a controller that can manage both measurement and communication operations across different frequency bands. The same controller unit handles both the first measurement unit and second communication unit, and can dynamically switch between operation modes, reducing the need for separate dedicated control circuits and thereby reducing overall device complexity while maintaining dual-band capabilities.

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

Data Source

PatentEP3780777B1User terminal apparatus, radio communication method and base station
Publication Date: 2026.05.13 NTT DOCOMO INC
  • EP3780777B1 patent drawingFigure 1
  • EP3780777B1 patent drawingFigure 2
  • EP3780777B1 patent drawingFigure 3

AI summary

A user terminal according to an aspect of the present disclosure includes a transmitting/receiving section that performs at least one of transmission and reception of a demodulation reference signal (DMRS) for a physical shared channel, and a control section that determines a power for the DMRS without taking account of a resource element to which the DMRS is not allocated, with reference to a table providing a definition of a ratio of a power (EPRE) for each resource element of the physical shared channel to an EPRE for the DMRS to which a certain number of CDM groups is applied. According to one aspect of the present disclosure, it is possible to use the same transmission power for data symbols and DMRS symbols even in NR.