LDPC Check Matrix Encoding with Flexible Lifting Factors

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Solution Overview

Problem

Existing computing methods for check matrices of LDPC codes require optimization to maintain a low bit-error-rate floor and reduce storage space while ensuring flexible code lengths.

Innovation Solution

An encoding method using a matrix with a lifting factor z, where submatrices include cyclic shift matrices based on an identity matrix, with cyclic shift values determined by specific functions to optimize performance and reduce bit-error-rate floor, and storage requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing computing methods for check matrices are used, then code flexibility is maintained, but bit-error-rate floor performance deteriorates and storage space increases

Engineering Contradiction:
Improvebit-error-rate floorVSAvoidstorage space
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies parameter changes by modifying the cyclic shift values in the check matrix through mathematical transformations. Specifically, it uses functions involving the maximum lifting factor zmax to transform the original check matrix into an equivalent form with optimized cyclic shift parameters, achieving lower bit-error-rate floors while reducing storage requirements for the matrix representation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent segments the check matrix into block matrices of size z×z, where each block is either an all-zero matrix or a cyclic shift matrix. This segmentation allows independent optimization of each block's cyclic shift value, enabling the system to achieve better error floor performance while maintaining flexible code lengths through the lifting factor mechanism.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If lifting factor z is increased to reduce storage space, then storage requirements decrease, but code length flexibility and performance optimization are limited

Engineering Contradiction:
Improvestorage spaceVSAvoidcode length flexibility
Core Design Contradiction:
Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent achieves universality by designing a check matrix structure that can support multiple code lengths through the lifting factor mechanism. The same base check matrix template can be used for different code lengths by adjusting the lifting factor z, allowing the system to maintain adaptability while using a compact stored representation that reduces space requirements.

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

Solution Approach 2:

The patent introduces dynamics by allowing the lifting factor z to be adjusted based on code length requirements. The check matrix structure dynamically adapts to different code lengths while maintaining the optimized cyclic shift pattern, enabling flexible code length support without sacrificing the storage space reductions achieved through the optimized representation.

Inventive Principle:
Principle #15Dynamics

3Reliability

If cyclic shift values are optimized to reduce bit-error-rate floor, then reliability improves, but computational complexity increases

Engineering Contradiction:
Improvebit-error-rate floorVSAvoidcomputational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses copying by storing only the essential parameters of the check matrix (such as the base pattern and lifting factor) rather than the complete expanded matrix. The actual check matrix is generated on-demand by copying and expanding the stored template with the appropriate lifting factor, reducing storage space while maintaining the ability to compute optimized cyclic shift values for reliable decoding.

Inventive Principle:
Principle #26Copying

Data Source

PatentUS11211952B2Encoding method, communication method, and apparatus
Publication Date: 2021.12.28 HUAWEI TECH CO LTD
  • US11211952B2 patent drawing
  • US11211952B2 patent drawing
  • US11211952B2 patent drawing

AI summary

The present disclosure relates 10 encoding methods, communication methods and apparatus. In one example method, a first information sequence is encoded by using a first matrix to obtain a second information sequence, where the first matrix meets a function related to a lifting factor and an element in Emax(H). The second information sequence is outputted.