Base Station Uplink Scheduling for Terminal Power Reduction

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Solution Overview

Problem

The application of beamforming by a base station with a super multi-element antenna increases the received Signal-Noise Ratio (SNR) of UL signals from terminals, but there are limitations on reducing terminal transmit power due to restricted installation spaces, traffic demand, and production costs, among other factors.

Innovation Solution

A base station device with a control section that selects and controls the ratio of low-speed and high-speed terminals for space-division multiplexing, using a combination table to optimize system throughput and reduce terminal transmit power by adjusting the number of terminals and reception points.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If beamforming is applied by a base station with a super multi-element antenna, then the received SNR of UL signals from terminals is increased, but the terminal transmit power cannot be reduced sufficiently due to limitations in installation space, traffic demand, and production cost

Engineering Contradiction:
Improveterminal transmit powerVSAvoidflexibility in terminal power reduction
Core Design Contradiction:
Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The invention segments terminals into two categories: first terminals (lower data rate requirements) and second terminals (higher data rate requirements). By segmenting the terminal population, the base station can apply different reception strategies to different terminal groups, enabling power reduction for first terminals while maintaining service quality for second terminals.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies local quality by providing differentiated reception services to different terminal groups. First terminals receive service optimized for power efficiency with space-division multiplexing, while second terminals receive service optimized for data rate. This localized optimization resolves the contradiction by tailoring reception parameters to specific terminal needs rather than applying uniform treatment.

Inventive Principle:
Principle #3Local quality

2Power

If the number of antenna elements is increased to reduce terminal transmit power, then beamforming gain is improved, but installation space becomes more restricted and production cost increases

Engineering Contradiction:
Improvebeamforming gainVSAvoidnumber of antenna elements
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The invention applies partial action by using a limited number of antenna elements (specifically 4 reception points) rather than deploying a full super multi-element antenna array. This partial deployment provides sufficient beamforming gain for the intended application while avoiding the complexity and cost of a complete high-element-count system.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The invention makes the reception points multi-functional by enabling them to serve both first terminals (for power-efficient communication) and second terminals (for high data rate communication) through space-division multiplexing. This universality allows the same physical infrastructure to achieve multiple objectives that would otherwise require separate systems.

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

3Productivity

If space-division multiplexing is used to accommodate more terminals, then system capacity is improved, but the ratio control between first and second terminals becomes critical for maintaining target transmit power

Engineering Contradiction:
Improvesystem throughputVSAvoidratio control complexity
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The invention implements feedback through the control section that monitors and adjusts the ratio of first to second terminals based on actual system conditions. The control section receives information about terminal characteristics and dynamically adjusts the allocation ratio to maintain target transmit power while optimizing system throughput.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention changes the operational parameter of terminal allocation ratio to optimize system performance. By adjusting the ratio of first terminals to second terminals as a controllable parameter, the system can adapt to varying traffic conditions and maintain optimal power efficiency and throughput characteristics.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach effectively reduces the transmit power of low-speed terminals while maintaining or enhancing system throughput, addressing limitations in existing technologies.

Implementation Method 1

a control section configured to select a plurality of terminals that transmit uplink signals to be received while space-division multiplexed by the plurality of antennas

Methodology Applied
Scientific EffectSpace-division multiplexing:

Implementation Method 2

Since application of beamforming by a base station which includes a super multi-element antenna increases the received Signal-Noise Ratio (SNR) of a UL signal from a radio communication terminal

Methodology Applied
Scientific EffectBeamforming:

Data Source

PatentEP3783942B1Base station device and communication method
Publication Date: 2026.01.07 NTT DOCOMO INC
  • EP3783942B1 patent drawingFigure 1
  • EP3783942B1 patent drawingFigure 2
  • EP3783942B1 patent drawingFigure 3

AI summary

A base station device includes a reception point that includes a plurality of antennas, and a control section that selects a plurality of terminals that transmit uplink signals to be received while space-division multiplexed by the plurality of antennas. The control section controls a ratio between a number of first terminals and a number of second terminals in selecting the plurality of terminals, the second terminals being terminals whose rate of the uplink signals is higher than a rate of the uplink signals of the first terminals, the ratio being controlled depending on a target transmit power configured for the first terminals.