Small-Protograph LDPC-CC Encoding for Fewer Redundant Bits

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Solution Overview

Problem

Current LDPC codes face challenges in efficiently encoding variable-length data due to the need for redundant bits when using block codes, leading to decreased data transmission efficiency, especially for small packet sizes, and existing solutions do not effectively address this issue.

Innovation Solution

Designing an LDPC-CC with a smaller protograph size by modifying the parity check polynomial and adding '1' to specific positions in the parity check matrix, allowing for improved error correction and reduced redundant bits through BP decoding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large block size LDPC-BC or large protograph size LDPC-CC is used, then error correction capability is improved, but the number of redundant bits transmitted increases significantly

Engineering Contradiction:
Improveerror correction capabilityVSAvoidnumber of redundant bits
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies dynamics by making the code structure adaptable to different packet sizes. The LDPC-CC uses a convolutional code structure with a small protograph that can dynamically encode variable-length information sequences without requiring fixed block sizes, allowing the code to adjust its behavior based on the actual data length while maintaining strong error correction capability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the fundamental parameters of the code design by using a convolutional structure with small protograph size instead of large block sizes. This parameter change allows the system to achieve good error correction performance with fewer redundant bits by optimizing the code rate and structure to match the actual transmission needs.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If padding processing or puncturing processing is performed on transmission information sequence, then LDPC code block length is adjusted, but coding rate changes and redundant sequence transmission occurs

Engineering Contradiction:
Improveadjustment of transmission information sequence lengthVSAvoiddata transmission efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent applies dynamics by implementing a convolutional code structure that naturally handles variable-length information sequences. The small protograph LDPC-CC can process packets of any length without requiring padding or puncturing operations, as the convolutional structure inherently supports continuous encoding of variable-length data streams.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent extracts the essential error correction functionality into a small protograph structure that can be efficiently applied to variable-length packets. By taking out the core coding function and implementing it through a compact convolutional structure, the system avoids the inefficiencies of large block codes while maintaining adaptability to different packet sizes.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3059869B1Encoding method, encoder, and decoder
Publication Date: 2018.09.26 PANASONIC HOLDINGS CORP
  • EP3059869B1 patent drawingFigure 1
  • EP3059869B1 patent drawingFigure 2
  • EP3059869B1 patent drawingFigure 3

AI summary

A low-density parity check convolution code (LDPC-CC) is made, and a signal sequence is sent after subjected to an error-correcting encodement using the low-density parity check convolution code. In this case, a low-density parity check code of a time-variant period (3g) is created by linear operations of first to 3g-th (letter g designates a positive integer) parity check polynomials and input data.