SRS Port-to-Symbol Mapping for Power Control Beyond Four Ports

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Solution Overview

Problem

Existing radio communication systems face challenges in appropriately performing SRS transmission using more than four SRS ports, particularly in future radio communication systems like 3GPP Rel. 18 and later versions, due to unclear configurations and transmission power control for SRS ports beyond four.

Innovation Solution

A terminal and base station are designed to receive configurations mapping different SRS ports to different OFDM symbols and equally divide transmission power by specific units, such as SRS ports, OFDM symbols, or subsets of ports, to maximize transmission power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of SRS ports is increased beyond four to support more layers in UL transmission, then the capacity and data rate are improved, but the transmission power control becomes unclear and cannot be appropriately performed

Engineering Contradiction:
ImproveUL transmission capacityVSAvoidSRS transmission power control
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the SRS ports into multiple groups, where each group is associated with a different OFDM symbol. This segmentation allows the transmission power to be controlled separately for each group, making power control manageable even when the total number of SRS ports exceeds four. The configuration information explicitly indicates the mapping relationship between SRS port groups and OFDM symbols, enabling clear power control mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a time dimension by mapping different SRS port groups to different OFDM symbols. This dimensional change allows the system to handle more than four SRS ports by distributing them across multiple time slots (OFDM symbols), thereby resolving the power control ambiguity that arises when simply increasing the number of ports in a single symbol.

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

2Ease of operation

If different SRS ports are mapped to different OFDM symbols, then the transmission power control becomes clear and manageable, but the configuration complexity increases

Engineering Contradiction:
ImproveSRS transmission power controlVSAvoidconfiguration complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent designs a universal configuration mechanism that can handle both cases of four or fewer SRS ports and more than four SRS ports. The configuration information structure is flexible and can adapt to different scenarios, providing a unified approach that simplifies operation while managing complexity through standardized multi-functional configuration elements.

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

3Productivity

If more than four SRS ports are used, then the UL transmission layers are increased, but the transmission power distribution becomes uncertain

Engineering Contradiction:
Improvenumber of UL transmission layersVSAvoidtransmission power distribution
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent segments the total transmission power into separate portions for each SRS port group, with each group mapped to a specific OFDM symbol. This segmentation enables clear power distribution across multiple ports by associating each port group with a dedicated time resource and power allocation, making the power distribution transparent and controllable even when exceeding four ports.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4697822A1Terminal, wireless communication method, and base station
Publication Date: 2026.02.18 NTT DOCOMO INC
  • EP4697822A1 patent drawingFigure 1
  • EP4697822A1 patent drawingFigure 2
  • EP4697822A1 patent drawingFigure 3

AI summary

A terminal according to one aspect of the present disclosure includes a receiving section that receives a configuration indicating that different Sounding Reference Signal (SRS) ports are mapped to different Orthogonal Frequency Division Multiplexing (OFDM) symbols, and a control section that equally divides transmission power of SRS by a specific unit. According to one aspect of the present disclosure, it is possible to appropriately perform SRS transmission using more than four SRS ports.