Downlink MIMO Layer Signaling for Efficient User Terminal Reception

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Solution Overview

Problem

The radio base station struggles to determine the maximum number of MIMO layers for communication with the user terminal, leading to potential unnecessary resource allocation and inefficient reception processing.

Innovation Solution

The user terminal and radio base station exchange control information to determine and share the maximum number of MIMO layers, allowing the user terminal to perform reception processing with suitable layers, and the base station to transmit control information indicating the number of MIMO layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the user terminal assumes a large number of MIMO layers for reception processing, then the reception capability is improved, but unnecessary arithmetic operations increase and processing efficiency decreases

Engineering Contradiction:
Improvereception capabilityVSAvoidprocessing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the number of MIMO layers based on actual communication conditions. The base station determines the appropriate number of MIMO layers through capability negotiation and signaling, and the user terminal adjusts its reception processing parameters accordingly. This allows the system to optimize between reception capability and processing efficiency by changing the operational parameters (number of layers) rather than maintaining a fixed large configuration.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements partial action by having the user terminal perform reception processing only for the actual number of MIMO layers used in communication, rather than assuming a maximum fixed number. The control section in the user terminal is configured to process only the necessary layers based on information received from the base station, avoiding excessive arithmetic operations on unused layers while maintaining the capability to handle higher layers when needed.

Inventive Principle:
Principle #16Partial or excessive action

2Device complexity

If the radio base station determines the maximum number of MIMO layers without user terminal feedback, then the resource allocation is simplified, but unnecessary resources are allocated and efficiency decreases

Engineering Contradiction:
Improveresource allocation complexityVSAvoidresource efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent implements feedback mechanisms where the user terminal reports its MIMO capability information to the base station through signaling messages. The base station uses this feedback information to determine the appropriate number of MIMO layers for resource allocation. This feedback loop allows the system to balance allocation simplicity with resource efficiency by using standardized capability reports rather than complex real-time negotiations.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies preliminary action by having the user terminal pre-configure and report its MIMO capability parameters to the base station before actual communication begins. The base station uses these pre-provided capability information to determine resource allocation parameters in advance, simplifying the resource allocation process while avoiding unnecessary resource assignment. This preliminary capability exchange eliminates the need for complex real-time determination mechanisms.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the user terminal performs reception processing for all possible MIMO layers, then the reception completeness is improved, but the arithmetic operation load increases unnecessarily

Engineering Contradiction:
Improvereception completenessVSAvoidarithmetic operation load
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamics by making the user terminal's reception processing configuration adaptive rather than static. The control section dynamically adjusts the number of processing layers based on real-time communication parameters received from the base station. This dynamic adaptation allows the system to maintain reception completeness for actively used layers while reducing arithmetic operation load by excluding inactive layers from processing, optimizing energy consumption based on actual operational needs.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3863189B1User terminal, wireless base station, and wireless communication method
Publication Date: 2026.04.15 NTT DOCOMO INC
  • EP3863189B1 patent drawingFigure 1
  • EP3863189B1 patent drawingFigure 2
  • EP3863189B1 patent drawingFigure 3

AI summary

Provided are a user terminal, a radio base station, and a radio communication method that are capable of performing reception processing using the number of suitable MIMO layers for a downlink. The user terminal includes a reception section that receives a downlink signal from the radio base station. Furthermore, the user terminal includes a control section that assumes the maximum number of MIMO layers based on control information that is included in the downlink signal. In a case where the downlink signal includes first control information indicating the number of MIMO layers, the control section assumes the maximum number of MIMO layers based on the first control information.