Punctured LDPC Coding for Finer WLAN MCS Rate Steps

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Solution Overview

Problem

The IEEE 802.11ax standard for wireless local area networks (WLANs) exhibits significant performance gaps between adjacent coding levels due to limited code rates, leading to suboptimal channel capacity utilization.

Innovation Solution

A method and system for encoding data using punctured low-density parity-check (LDPC) codes, which involves forming unpunctured codewords, removing punctured bits to create punctured codewords, and transmitting them based on specific thresholds, thereby introducing additional Modulation and Coding Scheme (MCS) levels to reduce gaps between coding levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If traditional coding levels with limited code rates are used, then implementation complexity is reduced, but performance gaps between adjacent coding levels increase

Engineering Contradiction:

Improvecoding level structureVSAvoidchannel capacity utilization

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent introduces intermediate code rates (e.g., 3/5, 4/7, 5/9) between traditional coding levels by applying puncturing patterns to base LDPC codes. This parameter change in code rate granularity reduces performance gaps between adjacent coding levels while maintaining a manageable number of code rate options, thus improving channel capacity utilization without excessively increasing implementation complexity

Inventive Principle:

Principle #35Parameter changes

2Reliability

If more code rates are introduced to reduce performance gaps, then channel capacity utilization improves, but system complexity increases

Engineering Contradiction:

Improvechannel capacity utilizationVSAvoidcoding scheme structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the code rate space by introducing intermediate rates through systematic puncturing of base LDPC codes. Instead of creating entirely new codes for each rate, the system divides the coding scheme into base codes and punctured variants, reducing overall system complexity while providing finer granularity in code rate selection

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent makes a single base LDPC code structure serve multiple code rates through different puncturing patterns. This multi-functionality allows the same underlying code to generate various code rates (e.g., 1/2, 3/5, 2/3, 4/7, 3/4, 5/9, 5/6) without requiring separate code designs for each rate, thereby improving channel capacity utilization while controlling system complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11588578B2System and method for encoding data using punctured low-density parity-check codes

Publication Date: 2023.02.21 SAMSUNG ELECTRONICS CO LTD

AI summary

A method for encoding or transmitting. In some embodiments, the method includes forming a set of one or more unpunctured codewords by coding a plurality of payload bits at a mother code rate, removing a plurality of punctured bits from the set of one or more unpunctured codewords to form a set of one or more punctured codewords, and transmitting the set of one or more punctured codewords. In some embodiments, the number of punctured bits exceeds a first threshold, or the number of punctured bits exceeds a second threshold.