Microwave Transmitter Power Control Using Buffer-State Feedback

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Solution Overview

Problem

Microwave radio links face challenges in reducing power consumption and radio interference, which increase operational and capital expenditures, and affect the total cost of ownership and mean-time-before-failure due to high power consumption and inefficient spectral usage.

Innovation Solution

The solution involves regulating the output power of a power amplifier based on the buffer state, such as fill level and priority of data, to adjust spectral efficiency and reduce power consumption, thereby minimizing interference and extending component lifespan.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If output power of power amplifier is increased to maintain data transmission during low buffer states, then transmission reliability is maintained, but power consumption increases and radio interference worsens

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamic power control by continuously monitoring buffer state and adjusting PA output power in real-time. The control module dynamically switches between high power mode (when buffer is full) and low power mode (when buffer is empty), making the power consumption adaptive to actual transmission needs rather than operating at fixed high power levels.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the power parameter of the PA based on buffer state conditions. By monitoring buffer fill level and data priority, the system adjusts the output power parameter to match actual transmission requirements, reducing power consumption during low-traffic periods while maintaining reliability during high-traffic periods.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If output power of power amplifier is increased to ensure data transmission, then transmission reliability is improved, but radio interference to neighboring systems increases

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidradio interference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system dynamically adjusts transmission power based on buffer state, reducing radio interference during low-traffic periods when high power is not needed. The control module switches between high and low power modes, making interference levels adaptive rather than constantly high.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the power parameter according to buffer conditions, reducing radio interference by lowering transmission power when buffer state allows. This parameter adaptation ensures reliability when needed while minimizing harmful interference during low-traffic periods.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If spectral efficiency is increased to improve data transmission rate, then productivity increases, but power consumption increases due to more complex signal processing

Engineering Contradiction:
Improvedata transmission rateVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by using high spectral efficiency only when necessary (buffer full condition). During low buffer states, the system uses lower spectral efficiency modes, reducing signal processing complexity and power consumption. This partial application of high-performance modes optimizes the trade-off between productivity and energy use.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The invention changes spectral efficiency parameters based on buffer state and data priority. By adapting modulation and coding schemes according to actual transmission needs, the system achieves high data rates when required while reducing processing complexity and power consumption during low-traffic periods.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If power amplifier operates at high power continuously, then transmission reliability is maintained, but component lifespan decreases due to increased thermal stress

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidcomponent lifespan
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The system implements periodic power adjustment based on buffer state monitoring. The PA operates at high power only during periods when buffer is full and data transmission is required, and switches to low power during idle periods. This periodic operation reduces cumulative thermal stress on components while maintaining reliability when needed.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The invention changes the power parameter of the PA based on buffer conditions, reducing thermal stress and extending component lifespan. By operating at lower power during low-traffic periods, the system decreases heat generation and thermal cycling, which are major factors in component degradation.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3295723B1Energy efficient transmitter power control
Publication Date: 2019.09.25 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3295723B1 patent drawingFigure 1
  • EP3295723B1 patent drawingFigure 2
  • EP3295723B1 patent drawingFigure 3

AI summary

A microwave transceiver comprising a data buffer, an ACM module, a PA, and an antenna. The ACM module configured to receive buffered data from the data buffer and to modulate the buffered data at a modulation format having a spectral efficiency, the PA configured to receive modulated buffered data from the ACM module, and to transmit amplified modulated buffered data, via the antenna, to a remote microwave transceiver at an output power. The modulation format is selected from a plurality of modulation formats based on a feedback signal from the remote microwave transceiver. The microwave transceiver further comprising a control module configured to monitor a buffer state of the data buffer, and to control the output power of the PA based on the buffer state.