CLDPC Parity Check Matrix Layout for High-Throughput Decoding

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Solution Overview

Problem

Existing error correction coding techniques for storage devices face challenges in balancing high error correction capability with decoding throughput and data storage density, often resulting in uncorrectable errors due to excessive redundancy or complex encoding/decoding operations.

Innovation Solution

The implementation of convolutional low-density parity-check (CLDPC) codes, which utilize a parity check matrix with multiple copies of a sub-matrix and a terminating portion to simplify operations, enable high decoding throughput and encodeability while maintaining a high error correction capability through windowed decoding processes and multiple decoders with varying power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a relatively large amount of redundancy information is used to increase error correction capability, then error correction capability is improved, but data decoding throughput may decrease due to additional computations

Engineering Contradiction:
Improveerror correction capabilityVSAvoiddata decoding throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The parity check matrix is divided into multiple sub-matrices arranged in a structured pattern, allowing the decoding process to be segmented into smaller operations. This segmentation reduces the computational complexity per operation while maintaining the overall error correction capability through the combined effect of multiple sub-matrices.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses a moderate amount of redundancy information that provides sufficient error correction capability without excessive computations. The structured LDPC code design achieves near-optimal error correction performance with a balanced redundancy level, avoiding both insufficient correction and excessive computational overhead.

Inventive Principle:
Principle #16Partial or excessive action

2Reliability

If a relatively large amount of redundancy information is used to increase error correction capability, then error correction capability is improved, but data storage density decreases

Engineering Contradiction:
Improveerror correction capabilityVSAvoiddata storage density
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent optimizes the redundancy ratio by carefully designing the parity check matrix structure and selecting appropriate code rates. The structured LDPC code achieves high error correction capability with an optimized redundancy level that maintains acceptable storage density, balancing the trade-off between reliability and storage efficiency.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the number of linear equations associated with a codeword is increased to generate additional redundancy information, then error correction capability is improved, but encoding and decoding operations become more complex

Engineering Contradiction:
Improveerror correction capabilityVSAvoidencoding and decoding operation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The parity check matrix is segmented into multiple sub-matrices with a structured arrangement pattern. This segmentation transforms the complex decoding problem into smaller, more manageable operations that can be executed efficiently, reducing the overall computational complexity while maintaining error correction capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The structured LDPC code uses repeated patterns of sub-matrices in the parity check matrix. This copying approach allows the use of standardized decoding algorithms that can be efficiently implemented, reducing complexity compared to designing and implementing unique decoding logic for each individual parity check equation.

Inventive Principle:
Principle #26Copying

4Quantity of substance

If existing ECC techniques are used to increase data storage density by reducing redundancy information, then data storage density is improved, but error correction capability decreases resulting in uncorrectable errors

Engineering Contradiction:
Improvedata storage densityVSAvoiderror correction capability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent optimizes the code rate and redundancy ratio by carefully designing the parity check matrix structure. The structured LDPC code achieves acceptable storage density while maintaining sufficient error correction capability through optimized parameter selection, avoiding the uncorrectable errors that result from excessive redundancy reduction in conventional codes.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS10367528B2Convolutional low-density parity-check coding
Publication Date: 2019.07.30 SANDISK TECHNOLOGIES LLC
  • US10367528B2 patent drawing
  • US10367528B2 patent drawing
  • US10367528B2 patent drawing

AI summary

In an illustrative example, a method includes receiving data to be processed in accordance with a convolutional low-density parity-check (CLDPC) code. The method also includes processing the data based on a parity check matrix associated with the CLDPC code. The parity check matrix includes a first portion and a second portion. The first portion includes a plurality of copies of a first sub-matrix that is associated with a first sub-code, and the second portion includes a copy of second sub-matrix that is associated with a second sub-code.