QC-LDPC Base Matrix Layout for Parallel Decoding and Code Quality

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current channel coding techniques, particularly Low Density Parity Check (LDPC) codes, face challenges in achieving high data throughput while efficiently managing encoding and decoding resources, especially in maintaining high parallelism and code quality.

Innovation Solution

The method involves creating a base matrix for an irregular QC-LDPC code by dividing rows into high and low-density sets, selecting columns to form orthogonal subrows, and puncturing high-weight columns to enable layered and flooding decoding, thereby achieving high parallelism and maintaining code quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high-weight columns are punctured to enable layered decoding, then parallelism during decoding is improved, but code quality may deteriorate

Engineering Contradiction:
Improvedecoding parallelismVSAvoidcode quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The base matrix rows are segmented into two sets: high-density rows and low-density rows. This segmentation enables different decoding strategies to be applied to different parts of the matrix, allowing layered decoding to be applied to low-density rows (improving parallelism) while high-density rows maintain code quality through alternative processing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different quality requirements are applied to different parts of the code structure. High-density rows are treated with one decoding approach while low-density rows receive another, allowing each region to be optimized for its specific characteristics. This local differentiation resolves the contradiction by not applying a uniform approach that would compromise overall code quality.

Inventive Principle:
Principle #3Local quality

2Productivity

If more columns are selected for orthogonal subrows, then decoding parallelism is improved, but the number of punctured information bits increases

Engineering Contradiction:
Improvedecoding parallelismVSAvoidpunctured information bits
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

Instead of puncturing all high-weight columns, only specific columns are selected for puncturing while others are retained. This partial action approach achieves sufficient parallelism improvement without the excessive loss of information that would result from more aggressive puncturing strategies.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If high-density rows are used extensively, then code performance is improved, but decoding complexity increases

Engineering Contradiction:
Improvecode performanceVSAvoiddecoding complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The row set is segmented into high-density and low-density portions, allowing the system to leverage the performance benefits of high-density rows while using low-density rows to reduce overall decoding complexity. This segmentation enables a balanced approach that neither fully exploits nor completely avoids high-density structures.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS11265014B2Method and apparatus for encoding and decoding LDPC codes
Publication Date: 2022.03.01 HUAWEI TECH CO LTD
  • US11265014B2 patent drawing
  • US11265014B2 patent drawing
  • US11265014B2 patent drawing

AI summary

Certain aspects of the present disclosure provide an efficiently decodable QC-LDPC code which is based on a base matrix, the base matrix being formed by columns and rows, the columns being dividable into one or more columns corresponding to punctured variable nodes and columns corresponding to non-punctured variable nodes. Apparatus at a transmitting side includes a encoder configured to encode a sequence of information bits based on the base matrix. Apparatus at a receiving side configured to receive a codeword in accordance with a radio technology across a wireless channel. The apparatus at the receiving side includes a decoder configured to decode the codeword based on the base matrix.