9B10B Line Coding Table for DC-Balanced Ethernet Transmission

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Solution Overview

Problem

Current 9B10B line coding methods in Ethernet systems suffer from high redundancy and inadequate DC balance, leading to performance deterioration due to channel noise, especially in optical communication systems.

Innovation Solution

A new convolutional line coding method is developed, which constructs a sequence set of 10-bit codewords, selects balanced and unbalanced sequences, performs Hamming distance detection, and generates a 9B10B code table with specific operation difference values, ensuring DC balance and reducing redundancy by limiting continuous 0s or 1s, thereby improving coding performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If 9B10B line coding is used, then coding efficiency is improved compared to 8B10B, but DC balance and control over continuous 0s or 1s are not ensured

Engineering Contradiction:
Improvecoding efficiencyVSAvoidDC balance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the parameters of the coding scheme by introducing operation difference value constraints and specific code table design rules that limit continuous 0s or 1s to at most 4 bits, thereby achieving both high coding efficiency and DC balance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different coding rules to different parts of the code table based on operation difference values (0, ±2, ±4), with specific constraints on continuous 0s or 1s for each category, ensuring local optimization of DC balance while maintaining overall coding efficiency

Inventive Principle:
Principle #3Local quality

2Device complexity

If conventional 9B10B coding is used, then coding simplicity is maintained, but performance deteriorates due to channel noise and lack of DC balance

Engineering Contradiction:
Improvecoding simplicityVSAvoidnoise performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces operation difference value as a new parameter to classify and organize code words, creating a structured approach that maintains coding simplicity while improving noise performance through controlled DC balance and limited continuous bits

Inventive Principle:
Principle #35Parameter changes

3Reliability

If code table is designed with operation difference value constraints, then DC balance is achieved, but code table complexity increases

Engineering Contradiction:
ImproveDC balanceVSAvoidcode table structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the code table into different categories based on operation difference values (0, ±2, ±4), with each segment having specific rules for continuous 0s or 1s limitation, making the complex code table manageable through systematic organization

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2293449B1Method and apparatus for generating a coding table
Publication Date: 2013.07.10 HUAWEI TECH CO LTD
  • EP2293449B1 patent drawingFigure 1
  • EP2293449B1 patent drawingFigure 2~3
  • EP2293449B1 patent drawing

AI summary

The present invention relates to communication technologies, and provides a method and an apparatus for line coding. A convolutional line coding method includes: constructing a sequence set, where the length of each sequence in the sequence set is n bits; selecting a balanced sequence in the sequence set, and obtaining source data of n-1 bits corresponding to the balanced sequence; performing Hamming distance detection for an unbalanced sequence in the sequence set to obtain source data of n-1 bits corresponding to the unbalanced sequence; sorting the balanced sequence and the unbalanced sequence according to an operation difference value, and generating a code table, where the source data of n-1 bits correspond to the sequence of n bits, and the code table is designed for line coding; and at time of encoding the source data of n-1 bits, obtaining a coding result of n bits according to a mapping relation in the code table. The corresponding apparatus is also provided.