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

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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 divided into two sets: high-density rows and low-density rows. This segmentation allows different decoding strategies to be applied to different parts of the matrix, enabling layered decoding on low-density rows while maintaining flooding decoding on high-density rows, thus achieving parallelism without sacrificing code quality

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different decoding approaches are applied to different regions of the matrix. Low-density rows undergo layered decoding with column puncturing to maximize parallelism, while high-density rows maintain flooding decoding to preserve code quality. This local differentiation resolves the contradiction between parallelism and 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 selected columns from the low-density rows are punctured. This partial action approach achieves sufficient parallelism for high-speed decoding while minimizing the loss of information bits, resolving the contradiction between parallelism and information preservation

Inventive Principle:

Principle #16Partial or excessive action

3Adaptability or versatility

If rate adaptation is implemented by removing rows, then versatility is improved, but encoding/decoding properties may be compromised

Engineering Contradiction:

Improverate adaptationVSAvoidencoding/decoding properties

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system dynamically adapts the code rate by selectively removing rows from the base matrix based on channel conditions and throughput requirements. The structured design with high-density and low-density row sets ensures that rate adaptation can be performed while maintaining the essential encoding/decoding properties of the LDPC code

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10567002B2Method and apparatus for encoding and decoding LDPC codes

Publication Date: 2020.02.18 HUAWEI TECH CO LTD

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.