LTE Base Station Power Saving via OFDM Symbol Detection

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Solution Overview

Problem

In LTE systems, the conventional method for sending downlink subframes often results in energy waste due to the continuous operation of transmitting channels, even when they carry no actual content, leading to unnecessary power consumption.

Innovation Solution

A method and system where a baseband subsystem or intermediate-frequency radio-frequency subsystem shuts down or decreases the power of OFDM symbols in a downlink subframe if they carry no actual content, distinguishing between symbols with and without content to conserve energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the transmitting channel operates continuously to send downlink subframes, then the system can maintain continuous communication capability, but energy is wasted when the channel carries no actual content

Engineering Contradiction:
Improvecommunication capabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The transmitting channel is activated periodically only when actual content needs to be transmitted, rather than operating continuously. The baseband subsystem checks each OFDM symbol to determine if it contains actual content, and the RF subsystem activates the transmitting channel only for symbols that require transmission, creating a periodic on-demand operation pattern that reduces energy waste while maintaining communication capability.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The transmitting channel transitions from a static continuous operation state to a dynamic state where it can be activated or deactivated based on real-time content requirements. The system dynamically adjusts the transmitting channel state by detecting whether OFDM symbols contain actual content, allowing the channel to adapt its operation to actual transmission needs and avoid energy waste during idle periods.

Inventive Principle:
Principle #15Dynamics

2Loss of energy

If the transmitting channel is shut down or power decreased for OFDM symbols without actual content, then energy consumption is reduced, but system complexity increases due to content detection requirements

Engineering Contradiction:
Improvepower consumptionVSAvoidcontent detection mechanism
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The baseband subsystem automatically performs content detection on each OFDM symbol and generates control information indicating whether actual content is present. This self-service mechanism eliminates the need for external detection systems, as the baseband subsystem inherently knows whether it has processed actual content for each symbol, thereby reducing overall system complexity while enabling energy-saving operations.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The baseband subsystem provides feedback to the RF subsystem about the content status of each OFDM symbol through control information. This feedback mechanism allows the RF subsystem to make informed decisions about transmitting channel activation without requiring complex independent detection capabilities, simplifying the overall system architecture while achieving energy savings through coordinated operation.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2900020B1Power-saving method and system
Publication Date: 2017.12.06 HUAWEI TECH CO LTD
  • EP2900020B1 patent drawingFigure 1
  • EP2900020B1 patent drawingFigure 2
  • EP2900020B1 patent drawingFigure 3~4

AI summary

The embodiments of the present invention disclose an energy-saving method, an energy-saving system, and a base station. The method includes: when no actual content is carried on an OFDM symbol in a subframe in an LTE system, shutting down a transmitting channel that is corresponding to the OFDM symbol or decreasing power of the transmitting channel that is corresponding to the OFDM symbol. Through the method, system and base station, a symbol that carries actual content may be distinguished from a symbol that carries no content; for the symbol that carries no content, power of a transmitting channel at the time corresponding to the symbol is decreased, or the transmitting channel at the time corresponding to the symbol is shut down. In this way, energy consumption of a system may be saved.