MIMO Configuration Switching for Power Efficiency in Mobile Transmitters

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Solution Overview

Problem

MIMO configurations in wireless communication systems, particularly in UEs, lead to increased current consumption and inefficiency due to multiple power amplifiers, which complicates battery life and form factor, especially when beam-forming is used, and existing solutions fail to autonomously optimize configurations based on current consumption.

Innovation Solution

A method and apparatus for controlling MIMO configurations in transmitters with multiple antennas and amplifiers, where a configuration processor monitors current consumption and autonomously selects between antenna-switching and beam-forming configurations, optimizing power usage by switching off or powering down amplifiers as needed, thereby reducing current consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If MIMO configuration with multiple power amplifiers is used, then spectral efficiency and system capacity are improved, but current consumption increases

Engineering Contradiction:
Improvespectral efficiencyVSAvoidcurrent consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic MIMO configuration switching between different modes (2x2, 2x1, 1x1) based on real-time channel conditions and current consumption thresholds. The system transitions from static to dynamic configuration, adapting the number of active transmit antennas and power amplifiers according to operational requirements, thereby optimizing the trade-off between spectral efficiency and power consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters including the number of active power amplifiers, MIMO configuration mode, and transmit antenna selection based on monitored current consumption levels and channel quality indicators. By adjusting these parameters dynamically, the system achieves optimal performance across varying operational conditions while managing power consumption effectively.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If beam-forming configuration is used, then communication performance is improved, but device complexity and form factor are worsened

Engineering Contradiction:
Improvecommunication performanceVSAvoidform factor
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic switching between beam-forming and antenna-switching configurations based on operational conditions. The system does not permanently commit to beam-forming but adapts the configuration dynamically, reducing the need for permanent complex hardware infrastructure while maintaining performance benefits when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system designs the transmitter to support multiple MIMO configurations (2x2, 2x1, 1x1) and both beam-forming and antenna-switching modes using the same physical hardware. This multi-functionality allows a single device to perform different operational modes, reducing the need for dedicated hardware for each function and thereby simplifying the overall form factor.

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

3Use of energy by moving object

If autonomous MIMO configuration selection is implemented, then power efficiency is improved, but control complexity increases

Engineering Contradiction:
Improvepower efficiencyVSAvoidcontrol complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The transmitter autonomously monitors its own current consumption and independently decides when to switch between different MIMO configurations without requiring external control signals. This self-service capability enables the system to optimize its own power efficiency by making configuration decisions based on real-time operational state, reducing dependency on network control while improving power management.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements a feedback mechanism where the transmitter continuously monitors current consumption and uses this information to trigger configuration changes. The feedback loop compares actual current consumption against predefined thresholds and automatically adjusts the MIMO configuration accordingly, creating a closed-loop control system that optimizes power efficiency through autonomous decision-making.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2834924B1MIMO configuration methods and apparatus
Publication Date: 2017.09.20 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2834924B1 patent drawingFigure 1~2
  • EP2834924B1 patent drawingFigure 3~4
  • EP2834924B1 patent drawingFigure 5

AI summary

Multiple-input multiple-output (MIMO) with multiple power amplifiers (404, 406) and antennas (408, 410) in a mobile transmitter, such as a user equipment for a cellular telephone communication system, has such great impacts on the transmitter's battery life, form factor, and complexity that it should not be used unless its benefits clearly outweigh its costs. Methods and apparatus of the invention enable to obtain the benefits of MIMO by beam-forming and antenna-switching without incurring the drawbacks of increased current consumption due to multiple power amplifiers.