LDPC Parity-Check Matrix Structure for Flexible Code Rates

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Solution Overview

Problem

Current LDPC encoding/decoding systems face challenges in supporting variable input lengths and coding rates, which affects their performance in high-speed digital communication systems prone to noise, fading, and inter-symbol interference.

Innovation Solution

The development of a method and apparatus for designing a parity check matrix and elementary matrix that enables LDPC encoding/decoding with high decoder throughput, allowing for flexible support of various codeword lengths and coding rates through balanced distribution of circulant permutation matrices and partial windowing-orthogonal structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional LDPC encoding/decoding systems are used, then basic error correction functionality is provided, but they cannot support variable input lengths and coding rates effectively

Engineering Contradiction:
Improvesupport for variable input lengths and coding ratesVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent designs a universal LDPC encoding/decoding system that can handle multiple input lengths and coding rates through a unified parity check matrix structure. The system uses a base matrix that can be extended to support different code lengths and rates, allowing a single system to perform multiple functions rather than requiring separate systems for each configuration.

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

Solution Approach 2:

The patent employs dynamic configuration of the parity check matrix where the matrix structure can be adapted based on the required input length and coding rate. The lifting operation allows the base matrix to be expanded dynamically to match different system requirements, enabling flexible adjustment of code parameters without fixed structural constraints.

Inventive Principle:
Principle #15Dynamics

2Productivity

If decoder throughput is increased to handle high-speed communication, then data transmission rate is improved, but decoding complexity and resource requirements increase

Engineering Contradiction:
Improvedecoder throughputVSAvoiddecoding complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the decoding process into parallel operations that can be executed simultaneously. By dividing the parity check matrix into blocks and processing them in parallel, the system increases throughput without proportionally increasing overall complexity. The segmented approach allows independent processing of different code blocks while maintaining manageable complexity for each segment.

Inventive Principle:
Principle #1Segmentation

3Productivity

If the parity check matrix is optimized for high decoder throughput, then decoding efficiency is improved, but flexibility in supporting various codeword lengths is reduced

Engineering Contradiction:
Improvedecoding efficiencyVSAvoidflexibility for various codeword lengths
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent uses a dynamic base matrix structure that can be lifted to different dimensions to support various codeword lengths. The base matrix is designed with properties that maintain decoding efficiency across different expansions, allowing the system to optimize for throughput while retaining adaptability through configurable lifting operations.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3586445B1Apparatus and method for channel encoding/decoding in communication or broadcasting system
Publication Date: 2021.05.26 SAMSUNG ELECTRONICS CO LTD
  • EP3586445B1 patent drawingFigure 1~4a
  • EP3586445B1 patent drawingFigure 4b~4c
  • EP3586445B1 patent drawingFigure 5

AI summary

A method for channel encoding in a communication or broadcasting system is provided. The method includes determining a block size Z, and performing encoding based on the block size and a parity check matrix corresponding to the block size, wherein the parity check matrix is determined based on a base matrix and a plurality of circulant permutation matrices, and wherein a part of a column index indicating a position of a non-zero element in each row of the base matrix includes an index according to mathematical expression 22 above.