PHY Preamble Bandwidth Signaling Beyond 160 MHz WLAN

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Solution Overview

Problem

Conventional wireless LAN standards lack a mechanism to notify communication in frequency bandwidths greater than 160 MHz, which is being explored in the IEEE802.11EHT standard.

Innovation Solution

A communication device is designed to transmit PHY frames with a preamble structure that includes Legacy and EHT fields, specifically an EHT-SIG-A field to indicate communication in a frequency band exceeding 160 MHz, using additional subfields in the EHT-SIG-A to signal this bandwidth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional wireless LAN standards are used, then compatibility with existing systems is maintained, but the ability to notify communication in frequency bandwidths greater than 160 MHz is lost

Engineering Contradiction:

Improvefrequency bandwidth notification capabilityVSAvoidpreamble structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent embeds the bandwidth indication information within the existing EHT-SIG-A field structure, nesting the new functionality inside the established preamble framework. The Bandwidth field is incorporated as part of the EHT-SIG-A1 or EHT-SIG-A2 subfields, allowing the system to convey 320 MHz bandwidth information without creating a separate notification mechanism.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent modifies the EHT-SIG-A field parameters to include bandwidth indication capability. By changing the EHT-SIG-A structure to include a Bandwidth field that can indicate 320 MHz operation, the system adapts existing parameters to support new frequency bandwidths while maintaining the overall preamble structure.

Inventive Principle:

Principle #35Parameter changes

2Loss of information

If the EHT-SIG-A field is used to indicate bandwidth, then backward compatibility is maintained, but the information capacity of the preamble is increased

Engineering Contradiction:

Improvebandwidth information transmissionVSAvoidpreamble information structure

Core Design Contradiction:

Loss of informationVSDevice complexity

Solution Approach 1:

The EHT-SIG-A field is designed to serve multiple functions: it provides legacy compatibility for older devices while simultaneously carrying new bandwidth indication information for EHT devices. The same field structure serves both legacy interpretation and extended functionality, allowing universal compatibility across different device generations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent adds information capacity by utilizing previously unused or reserved bits within the EHT-SIG-A structure. By incorporating bandwidth indication in the EHT-SIG-A1 or EHT-SIG-A2 subfields, the system adds a new dimension of information transmission without fundamentally altering the existing preamble architecture.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS12549416B2Communication device, communication method, and computer-readable storage medium

Publication Date: 2026.02.10 CANON KK

AI summary

A communication device communicates a physical (PHY) frame including a preamble and a data field. The preamble includes a Legacy Short Training Field (L-STF), a Legacy Long Training Field (L-LTF), a Legacy Signal Field (L-SIG), an EHT (Extremely High Throughput) Signal Field (EHT-SIG-A), an EHT Short Training Field (EHT-STF), and an EHT Long Training Field (EHT-LTF), and the EHT-SIG-A includes at least one subfield indicating that the communication device performs communication in a frequency band more than 160 MHz.