LDPC Tone Mapping Flexibility in Wireless LAN

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Solution Overview

Problem

Existing LDPC tone mapping methods in wireless LAN systems require the tone spacing parameter (DTM or DTM_DCM) to be a factor of the number of data tones (NSD), limiting flexibility and increasing implementation complexity.

Innovation Solution

The method allows LDPC tone mapping without constraining the tone spacing parameter (DTM or DTM_DCM) to be a factor of NSD, using the ceil and floor functions to determine tone indices, enabling frequency diversity even when the parameter is not a factor, thus enhancing LDPC tone mapping operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the tone spacing parameter (DTM or DTM_DCM) is constrained to be a factor of NSD, then the LDPC tone mapping can be performed using existing methods, but the implementation complexity increases and flexibility is limited

Engineering Contradiction:

Improveflexibility of tone spacing parameterVSAvoidimplementation complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent changes the parameter constraint condition by allowing DTM or DTM_DCM to take any positive integer value without requiring it to be a factor of NSD. This parameter change enables greater flexibility in tone spacing selection while maintaining compatibility with existing LDPC tone mapping operations through mathematical adjustments in the mapping equations.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If the tone spacing parameter is not constrained to be a factor of NSD, then implementation complexity is reduced and flexibility is increased, but existing LDPC tone mapping methods cannot be directly applied

Engineering Contradiction:

Improveease of implementationVSAvoidcompatibility with existing methods

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent segments the tone mapping process into distinct stages: first performing constellation mapping on the bitstream, then applying LDPC tone mapping with the relaxed DTM parameter. This segmentation allows each stage to operate independently with its own optimized parameters, enabling the use of non-factor DTM values while maintaining overall system compatibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic adjustment mechanisms in the LDPC tone mapping equations, where the mapping indices are calculated using modular arithmetic and scaling factors that adapt to any DTM value. This dynamic approach allows the system to handle variable tone spacing parameters flexibly without requiring rigid structural changes to the overall communication framework.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12063112B2Method and device for receiving PPDU, for which LDPC tone mapping has been performed, in wireless LAN system

Publication Date: 2024.08.13 LG ELECTRONICS INC

AI summary

Proposed are a method and a device for receiving a PPDU, for which LDPC tone mapping has been performed, in a wireless LAN system. Specifically, a reception STA receives a PPDU including a data field from a transmission STA and decodes the data field. The data field is received through a first RU. Data tones included in the data field are LDPC tone-mapped to the first RU on the basis of a first parameter.