WLAN Preamble Control Signal for Version Detection

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Solution Overview

Problem

Existing wireless communication devices face challenges in efficiently and robustly detecting the version of IEEE 802.11 wireless local area network (WLAN) used in a communication frame, especially with the increasing demand for high data rates and backward compatibility.

Innovation Solution

A control signal is introduced within the preamble of a transmission, which includes a Legacy Signal (SIG) field and an identifier symbol or field. This control signal enables automatic detection of the wireless network version, ensuring compatibility with legacy systems and allowing for the correct interpretation of signaling information and payload data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a control signal with identifier symbol is added to enable automatic WLAN version detection, then detection accuracy and reliability are improved, but device complexity and signal structure complexity increase

Engineering Contradiction:
ImproveWLAN version detection reliabilityVSAvoidcontrol signal structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The identifier symbol is nested within the existing preamble structure by being generated from the Legacy Signal (L-SIG) symbol through cyclic shifting. This embedding approach allows version detection functionality to be added without creating a completely separate signal structure, thereby improving detection reliability while minimizing the increase in overall system complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The identifier symbol acts as an intermediary element that bridges legacy signal compatibility and new version detection requirements. By deriving the identifier from the existing L-SIG symbol through a deterministic transformation (cyclic shift), the system enables reliable version detection while maintaining compatibility with legacy devices that expect the standard L-SIG format.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If version detection is performed at an early stage after PPDU detection, then interpretation and decoding efficiency are improved, but detection precision requirements increase

Engineering Contradiction:
Improvesignal interpretation efficiencyVSAvoidversion detection precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The identifier symbol is prepared in advance within the preamble structure before the actual data transmission begins. By embedding the version identifier early in the signal structure (in the L-SIG symbol region), the receiver can perform version detection immediately after PPDU detection without needing to wait for or process the entire data payload, thus improving interpretation efficiency while maintaining precision through the use of dedicated detection bits.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4539538A1Preamble with detectable WLAN version identification
Publication Date: 2025.04.16 HUAWEI TECH CO LTD
  • EP4539538A1 patent drawingFigure 1A
  • EP4539538A1 patent drawingFigure 1B
  • EP4539538A1 patent drawingFigure 1C

AI summary

Systems and methods for generating a control signal for automatic wireless network version detection of a transmission. The control signal enables a receiver to detect the wireless network version detection of the transmission, so that the proper wireless network version is used for interpreting signaling information and decoding of the payload of the transmission. In some examples, the control signal is within a preamble of the transmission. The wireless network version can be an IEEE 802.11 version, such as proposed IEEE 802.11be. The control signal is compatible with legacy systems and can indicate the legacy signaling information by way of a Legacy Signal (SIG) (L-SIG) symbol. In some examples, the control signal can indicate the wireless network version by using an identifier symbol which is generated from at least part of, but is not identical to, the L-SIG symbol.