Wireless LAN PPDU RU Allocation Using Discontiguous Subcarriers

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Solution Overview

Problem

Existing wireless LAN technologies face challenges in improving transmission rates, reliability, and reducing latency, particularly in supporting low latency and ultra-high reliability (UHR) with efficient utilization of multiple bands and spatial streams.

Innovation Solution

The method involves generating and transmitting a PPDU within a 40MHz frequency bandwidth using resource units (RUs) that include discontiguous subcarriers, with their locations indicated in an ascending order based on the lowest subcarrier, and processing such RUs at the receiving station.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If discontiguous subcarriers are used in RUs, then transmission power and throughput are improved, but signaling overhead for RU allocation increases

Engineering Contradiction:
Improvetransmission throughputVSAvoidsignaling overhead
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The 40MHz frequency bandwidth is segmented into multiple RUs with discontiguous subcarriers. Each RU is independently allocated to different STAs, allowing flexible resource distribution. The RU allocation subfield indicates locations of multiple RUs by specifying the lowest subcarrier index of each RU, enabling efficient representation of fragmented frequency resources.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension for RU allocation representation by indicating RU locations through the lowest subcarrier index in ascending order. This dimensional approach allows the system to efficiently represent discontiguous subcarrier allocations without requiring exhaustive signaling of all subcarrier positions, thereby reducing overhead while maintaining flexibility.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Area of stationary object

If discontiguous subcarriers are used in RUs, then transmission coverage is improved, but device complexity increases

Engineering Contradiction:
Improvetransmission coverageVSAvoidprocessing complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

Different RUs within the 40MHz bandwidth are allocated to different STAs based on their specific requirements and channel conditions. Each RU has localized subcarrier assignments that are optimized for the receiving STA's capabilities and channel quality, allowing tailored transmission parameters for each user while maintaining overall system efficiency.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The RU allocation information is prepared and indicated in advance within the PPDU structure using the RU allocation subfield. The lowest subcarrier indices of all RUs are sorted in ascending order and encoded before transmission, allowing receiving STAs to efficiently decode and process the allocation information without complex real-time calculations.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4668653A1Method and device for PPDU transmission and reception in wireless LAN system
Publication Date: 2025.12.24 LG ELECTRONICS INC
  • EP4668653A1 patent drawingFigure 1
  • EP4668653A1 patent drawingFigure 2~3
  • EP4668653A1 patent drawingFigure 4~5

AI summary

A method and a device for transmitting and receiving a PPDU in a wireless LAN system are disclosed. The method performed by means of a first STA, according to one embodiment of the disclosure, may comprise the steps of: generating a physical protocol data unit (PPDU) to be transmitted within a 40MHz frequency bandwidth; and transmitting the PPDU to a second STA.