PHY Preamble Signal Classification for Wi-Fi Coexistence

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Solution Overview

Problem

In wireless communication networks, especially with the introduction of new Wi-Fi standards like High Efficiency Wi-Fi (HEW), there is a challenge in coexistence and compatibility with legacy systems, as existing methods require additional signaling to distinguish between different transmission standards, leading to increased packet overhead and potential misclassification of signals.

Innovation Solution

The implementation of a signal classification system that analyzes characteristics of the PHY preamble, such as data rate, orientation of OFDM symbols, and length fields, to differentiate between various IEEE 802.11 standards, including legacy and HEW systems, allowing devices to defer processing of unintended signals and minimize overhead by using repeated fields or modifying length fields to ensure compatibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If additional signaling is introduced to distinguish between different transmission standards, then signal classification accuracy is improved, but packet overhead increases

Engineering Contradiction:
Improvesignal classification accuracyVSAvoidpacket overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent uses repeated L-SIG fields as copies within the PHY preamble to enable signal classification. By repeating the L-SIG field multiple times, receiving devices can analyze the repeated copies to determine whether the transmission follows legacy or HEW standards, achieving accurate classification without adding substantial overhead beyond the necessary repetitions

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent modifies parameters of existing fields rather than introducing completely new signaling structures. Specifically, it changes the number of repetitions of the L-SIG field and uses different rate values in repeated fields to indicate HEW transmissions, while maintaining backward compatibility with legacy devices that interpret these parameter changes according to their standard

Inventive Principle:
Principle #35Parameter changes

2Productivity

If new Wi-Fi standards are introduced to address increased performance demands, then system performance is improved, but compatibility with legacy systems becomes more difficult

Engineering Contradiction:
Improvesystem performanceVSAvoidcompatibility with legacy systems
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent makes the PHY preamble structure universal across both legacy and HEW standards by using repeated L-SIG fields that can be interpreted differently by different device types. Legacy devices see standard repeated fields, while HEW devices recognize specific patterns (like non-legacy rates in repeated fields) to identify HEW transmissions, enabling one structure to serve multiple standards

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent performs signal classification at the PHY preamble level before MAC layer processing occurs. By analyzing the repeated L-SIG fields in the physical layer preamble, devices can determine the transmission standard early in the reception process, allowing them to prepare appropriate processing paths in advance and avoid misclassification issues that would arise later

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If signal classification is performed using existing methods, then device complexity is reduced, but misclassification of signals occurs

Engineering Contradiction:
Improveclassification method complexityVSAvoidsignal classification reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the receiving device analyzes the repeated L-SIG fields, determines the transmission standard based on specific criteria (such as rate values or repetition patterns), and then uses this classification information to guide subsequent processing decisions. This feedback loop ensures that classification decisions are made systematically rather than through ad-hoc methods, improving reliability

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies partial action by focusing classification efforts only on specific aspects of the repeated L-SIG fields rather than analyzing the entire packet structure. By examining only the relevant portions of the preamble (the repeated L-SIG fields with specific rate values), the system achieves reliable classification without the complexity of comprehensive packet analysis

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3205062B1Systems and methods for signal classification
Publication Date: 2019.07.24 INTEL CORP
  • EP3205062B1 patent drawingFigure 1A
  • EP3205062B1 patent drawingFigure 1B~1C
  • EP3205062B1 patent drawingFigure 1D~1E

AI summary

This disclosure describes systems, and methods related to signal classification in a wireless communication network. A first computing device comprising one or more processors and one or more transceiver component may receive a signal transmission packet comprising a physical layer (PHY) preamble. The first computing device may identify within the PHY preamble, one or more signal (SIG) fields, wherein at least one of the one or more SIG fields includes at least a length field indicating a length of the signal transmission packet. The first computing device may determine based at least in part on the length field, that the signal transmission packet is associated with a predetermined communication standard utilized to transmit the signal transmission packet. The first computing device may decode the signal transmission packet based at least in part on the determination that the signal transmission packet is associated with the predetermined communication standard.