Cross-Layer Modulation for DSL Power Reduction

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Solution Overview

Problem

Current DSL technologies face challenges in achieving high bit rates and reducing crosstalk, leading to increased energy consumption and costs, particularly in environments with fluctuating crosstalk and poor cabling quality, which hinders widespread adoption of IPTV services.

Innovation Solution

The method involves cross-layer modulation (CLM) for efficient bit manipulation and power reduction by scrambling and descrambling data, allowing for reduced transmission power while maintaining data integrity, applicable in both leased line and burst transmission scenarios, using existing transceiver technology.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If transmission power is reduced to save energy and reduce crosstalk, then energy consumption and crosstalk are decreased, but transmission reliability and data integrity may deteriorate

Engineering Contradiction:
Improvetransmission powerVSAvoiddata integrity
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the power levels of individual OFDM symbols based on their content characteristics. Symbols containing only parity bits are transmitted at reduced power, while symbols with user data are transmitted at full power. This selective power adjustment maintains data integrity for actual communications while significantly reducing overall energy consumption and crosstalk in the DSL system.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system dynamically determines transmission power levels on a per-symbol basis rather than using a fixed power level for all symbols. The power adapter module dynamically adjusts power levels based on the proportion of user data versus parity bits in each OFDM symbol, enabling the system to adapt to varying traffic conditions and maintain reliability while reducing energy consumption.

Inventive Principle:
Principle #15Dynamics

2Productivity

If bandwidth is broadened to achieve higher bit rates, then data transmission speed increases, but loop attenuation and crosstalk increase

Engineering Contradiction:
Improvebit rateVSAvoidcrosstalk
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the power parameter of OFDM symbols containing only parity bits to a reduced level, while maintaining full power for symbols with user data. This selective power reduction decreases the overall electromagnetic interference and crosstalk in the DSL loop, enabling the system to operate at broader bandwidths with higher bit rates without excessive interference.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the potentially harmful presence of parity bits (which consume bandwidth and generate interference) into a beneficial opportunity for power reduction. By identifying symbols that contain only parity bits and transmitting them at reduced power, the system reduces overall crosstalk and enables higher data rates without proportionally increasing interference.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Object-generated harmful factors

If power back-off is applied to reduce crosstalk, then transmission power is decreased, but transmission stability and SNR may fluctuate

Engineering Contradiction:
ImprovecrosstalkVSAvoidtransmission stability
Core Design Contradiction:
Object-generated harmful factorsVSStability of the object's composition

Solution Approach 1:

The system dynamically adjusts power levels on a per-symbol basis rather than applying a static power back-off. The power adapter module continuously monitors and adjusts power levels based on the actual content of each OFDM symbol, maintaining transmission stability by ensuring that symbols with user data receive full power while only reducing power for symbols with only parity bits.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the power parameter dynamically based on symbol content, maintaining power stability for symbols containing user data while reducing power only for symbols with only parity bits. This selective parameter change reduces crosstalk without causing fluctuations in transmission stability or SNR for active data communications.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2150010B1Method and device for reducing the transmission power on a digital subscriber line
Publication Date: 2017.09.06 ADTRAN GMBH
  • EP2150010B1 patent drawingFigure 1
  • EP2150010B1 patent drawingFigure 2
  • EP2150010B1 patent drawingFigure 3

AI summary

A method and a device for data processing are provided, said method comprising the steps of (a) at least one bit of the data is manipulated (405); (b) it is checked whether the manipulation is admissible (406); and (c) if the manipulation is admissible, the manipulated data is transmitted (409). Furthermore, a communication system is suggested comprising said device.