Convolutional Line Coding for DC-Balanced 9B10B Transmission
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Solution Overview
Problem
Current 9B10B line coding methods suffer from high redundancy and inadequate DC balance, making them unsuitable for reliable data transmission in Ethernet systems, especially due to errors caused by channel noise.
Innovation Solution
A convolutional line coding method that constructs a sequence set, selects balanced and unbalanced sequences, performs Hamming distance detection, and generates a code table to ensure low redundancy and controlled DC components, improving coding performance by restricting continuous 0s or 1s through a mapping relation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If 8B10B line coding is used, then DC balance is improved, but coding efficiency deteriorates due to 20% redundancy
Solution Approach 1:
The patent changes the coding parameters by using 9B10B coding instead of 8B10B coding, adjusting the code rate from 0.8 to 0.9. This parameter change reduces redundancy from 20% to 10% while maintaining DC balance through careful selection of codewords with controlled weight distribution, thereby improving coding efficiency without sacrificing DC balance.
2Productivity
If 64B/66B or 64B/65B line coding is used, then coding efficiency is improved, but DC balance deteriorates and DC components increase
Solution Approach 1:
The patent changes the coding scheme from 64B/66B or 64B/65B to 9B10B coding, fundamentally altering the code structure and rate. This parameter change enables achieving both high coding efficiency (90% code rate) and good DC balance by carefully designing the codeword set with controlled weight distribution and transitioning between codewords to limit DC component accumulation.
Solution Approach 2:
The patent applies local quality by differentiating between information bits and control bits in the 9B10B code structure. The control bits are specifically designed to adjust the weight of codewords and control transitions, providing localized control over DC balance properties while maintaining high overall coding efficiency.
3Device complexity
If traditional 9B10B line coding is used, then coding simplicity is maintained, but reliability deteriorates due to error susceptibility from channel noise
Solution Approach 1:
The patent applies preliminary action by pre-designing and selecting specific balanced and unbalanced sequences with optimal Hamming distance properties before actual data transmission. These pre-selected sequences form a code table that inherently provides error detection capability, allowing the receiver to identify and correct errors without complex real-time processing, thus maintaining coding simplicity while improving reliability.
Solution Approach 2:
The patent implements feedback through the structured code table design where the relationship between balanced and unbalanced sequences provides implicit error detection. When transmission errors occur, the receiver can detect inconsistencies by checking against the predetermined code table structure, and the system can request retransmission or correct errors based on this feedback mechanism.
Data Source
AI summary
The present invention provides a convolutional line coding method, including: 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.