LDPC Encoder Matrix Layout for Parallel Parity Generation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing LDPC encoding processes have high calculation complexity, particularly in the encoding phase, which limits processing rate and efficiency, especially when generating parity symbol sequences, and are not well-suited for parallel processing due to sequential calculation requirements.

Innovation Solution

The proposed encoding apparatus reduces calculation complexity by structuring the parity check matrix with specific submatrices, including a lower triangular matrix and sparse matrices, allowing for the generation of parity symbol sequences in a way that facilitates parallel processing, and optimizing the structure to enhance encoding rate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If LDPC encoding is performed by multiplying data symbol sequence with generator matrix, then encoding can be realized, but calculation complexity becomes order O(n2) which is too high

Engineering Contradiction:
Improveencoding rateVSAvoidcalculation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The parity check matrix H is segmented into submatrices with specific structures (lower triangular matrix Q, diagonal matrix R, and zero matrix S). This segmentation allows the encoding process to be divided into independent parallel operations, reducing calculation complexity from O(n2) to O(n) while maintaining encoding functionality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the structural parameters of the parity check matrix by enforcing specific patterns (lower triangular structure for Q, diagonal structure for R). This parameter change enables the use of efficient algorithms that exploit the matrix structure, significantly reducing the computational burden of encoding operations.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If sequential calculation is used for encoding, then calculation can be performed, but processing rate is limited and parallel processing is not suitable

Engineering Contradiction:
Improveprocessing rateVSAvoidparallel processing capability
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

By segmenting the parity check matrix into independent submatrices (Q, R, S) with defined structures, the patent enables the encoding process to be split into parallel computational streams. Each submatrix operation can be performed simultaneously, making the system suitable for parallel processing architectures and significantly improving processing rate.

Inventive Principle:
Principle #1Segmentation

3Reliability

If general LDPC encoding method is used, then encoding can be performed, but calculation complexity is high which limits efficiency

Engineering Contradiction:
Improveerror correction performanceVSAvoidcalculation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent modifies the parameters of the parity check matrix by imposing specific structural constraints (lower triangular form for Q, diagonal form for R). These parameter changes maintain the error correction capabilities of LDPC codes while enabling more efficient encoding algorithms that reduce calculation complexity from O(n2) to O(n), thereby improving overall encoding efficiency.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS8966351B2Encoding apparatus, encoding method and semiconductor memory system
Publication Date: 2015.02.24 KIOXIA CORP
  • US8966351B2 patent drawing
  • US8966351B2 patent drawing
  • US8966351B2 patent drawing

AI summary

According to one embodiment, an encoding apparatus includes an input unit and a generation unit. The input unit inputs a data symbol sequence containing q(N−J) symbols (q, J, and N are integers, N>J). The generation unit generates a codeword containing qN symbols by adding a parity symbol sequence containing qJ symbols to the data symbol sequence. The codeword satisfies parity check equations of a parity check matrix of qJ rows×qN columns. A first submatrix of qJ rows×qJ columns that corresponds to the parity symbol sequence in the parity check matrix includes a second submatrix. The second submatrix includes a first identity matrix of qL rows×qL columns (L is an integer, J>L) and a first non-zero matrix of q(J−L) rows×qL columns.