Structured LDPC Coding with Variable Expansion for Flexible Block Sizes

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Solution Overview

Problem

Existing LDPC coding technologies face challenges in accommodating various flexible lengths of code blocks, leading to low flexibility in data sequence processing.

Innovation Solution

A method and apparatus for data processing with structured LDPC codes, which involves determining a coding expansion factor based on the code block size, a parameter kb of a basic check matrix, and a positive integer value p, allowing for flexible LDPC encoding and decoding across different code block sizes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed basic check matrix is used for LDPC coding, then the coding structure is simple and manageable, but the system cannot accommodate various flexible lengths of code blocks

Engineering Contradiction:
Improveflexibility in code block sizeVSAvoidcoding system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the expansion factor z variable rather than fixed. The expansion factor is determined based on the code block size N, allowing the LDPC coding system to adapt dynamically to different code block lengths. This is achieved through the relationship z = N/kb, where kb is the code rate parameter, enabling the system to flexibly adjust to various code block sizes while maintaining a manageable basic check matrix structure

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter z (expansion factor) according to different code block sizes. By varying z based on the code block length N and the parameter kb, the system can accommodate flexible code block sizes. The basic check matrix Hb remains fixed with dimensions mb×nb, but the actual check matrix H is generated by expanding Hb with different z values, thus changing the code length while keeping the base structure simple

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If multiple basic check matrices are stored to support different code block sizes, then flexibility is improved, but memory storage requirements and system complexity increase

Engineering Contradiction:
Improvesupport for various code block sizesVSAvoidmemory storage requirement
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent makes a single basic check matrix Hb universal by using it to generate check matrices for different code block sizes through variable expansion factor z. The same basic check matrix Hb can produce LDPC codes of different lengths by adjusting z, eliminating the need to store multiple different basic check matrices. This multi-functional approach allows one matrix to serve multiple code length requirements

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent segments the code block size N into a base parameter kb and a variable expansion factor z, where N = kb × z. This segmentation allows the system to handle different code block sizes by varying only z while keeping kb and the basic check matrix Hb fixed, thereby reducing memory storage requirements compared to storing complete check matrices for each possible code block size

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3457574B1Data processing method and device for structured LDPC code
Publication Date: 2025.04.23 ZTE CORP
  • EP3457574B1 patent drawingFigure 1
  • EP3457574B1 patent drawingFigure 2
  • EP3457574B1 patent drawingFigure 3

AI summary

The embodiments of the present disclosure provide a method and an apparatus for data processing with structured LDPC codes. The method includes: obtaining a code block size for structured LDPC coding; determining a coding spread factor z based on at least one of the code block size, a parameter kb of a basic check matrix, a positive integer value p or the basic check matrix having mb rows and nb columns; and encoding a data sequence to be encoded, or decoding a data sequence to be decoded, based on the basic check matrix and the coding spread factor. The present disclosure is capable of solving the problem in the related art associated with low flexibility in data processing with LDPC coding and improving the flexibility in data processing with LDPC coding.