802.11 CSI Acquisition for Terminal Positioning

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Solution Overview

Problem

Existing 802.11 network-based CSI collection methods are limited in providing comprehensive Channel State Information (CSI) for terminal positioning, as CSI is tightly coupled with data reception and cannot be used for positioning applications, resulting in reduced positioning accuracy.

Innovation Solution

The implementation of a service request interface and asynchronous notification interface on STA devices allows for independent CSI collection and feedback, enabling the STA device to listen to multiple channels and extract CSI from PPDU signals, providing more comprehensive CSI for terminal positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If CSI collection is implemented using prior-art 802.11 data reception methods, then CSI can be obtained, but the collected CSI is limited to only the current operating channel and cannot be used for positioning applications

Engineering Contradiction:
Improvecompleteness of CSIVSAvoidapplicability of CSI to positioning
Core Design Contradiction:
Loss of informationVSAdaptability or versatility

Solution Approach 1:

The patent segments the CSI collection process into independent channel listening tasks. The service request program divides the positioning requirement into multiple channel listening requests, each targeting specific channels and AP devices. This allows comprehensive CSI collection across multiple channels rather than being limited to a single operating channel.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts CSI collection from the data reception process and creates an independent positioning function. The CSI obtaining module operates separately from the data reception module, allowing CSI to be collected specifically for positioning purposes without being constrained by data transmission requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If the STA device stays on its current operating channel to receive and send data, then data transmission is maintained, but the STA device can only detect PPDU on the current channel, limiting CSI collection

Engineering Contradiction:
Improvedata transmission efficiencyVSAvoidpositioning accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent implements dynamic channel switching capability. The STA device can dynamically switch between its current operating channel and other channels in the channel listening list based on positioning requirements. This dynamic behavior allows the device to collect CSI from multiple channels while maintaining data transmission on the original channel when not actively positioning.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The service request program pre-configures a channel listening list containing multiple channels and target AP devices before positioning begins. This preliminary preparation enables the CSI obtaining module to efficiently switch to required channels without real-time decision delays, improving both positioning accuracy and efficiency.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the STA device joins and stays on an 802.11 AP network for data transmission, then stable data communication is achieved, but CSI collection is restricted to that specific network's channel

Engineering Contradiction:
Improvedata transmission stabilityVSAvoidcompleteness of CSI for positioning
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent introduces an intermediary CSI obtaining module that acts as a bridge between the data transmission system and positioning requirements. This module can collect CSI from multiple AP devices across different channels without requiring the STA device to join those networks, thus maintaining data transmission stability on the original network while gathering comprehensive positioning data.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Measurement precision

If CSI is tightly coupled with PPDU demodulation for data reception, then signal quality is improved, but CSI cannot be independently used for positioning applications

Engineering Contradiction:
Improvesignal demodulation qualityVSAvoidCSI reusability for positioning
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent extracts the CSI obtaining function from the PPDU demodulation process and places it in an independent CSI obtaining module. This extracted module can collect CSI through dedicated channel listening operations separate from data reception, allowing the collected CSI to be independently utilized for positioning applications without being tied to active data transmission.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3537639B1CSI acquisition method and device for 802.11-based network
Publication Date: 2022.12.21 HUAWEI TECH CO LTD
  • EP3537639B1 patent drawingFigure 1~2
  • EP3537639B1 patent drawingFigure 3~4
  • EP3537639B1 patent drawingFigure 5

AI summary

Relating to the field of communications technologies, the present invention discloses an 802.11 network-based CSI obtaining method and apparatus, so as to provide a CSI obtaining mechanism that addresses a positioning requirement, to improve accuracy of a terminal positioning process by providing more comprehensive CSI for a terminal. The method in the present invention includes: receiving, by a CSI obtaining module through a service request interface, a request message sent by a service request program; extracting, by the CSI obtaining module according to a channel listening linger time, on all to-be-listened-on channels recorded in a channel listening list, CSI from PPDUs sent by all target AP devices recorded in a target AP device list; and when a group of CSI is collected, sending, by the CSI obtaining module, the group of CSI to the service request program through an asynchronous notification interface. The present invention is applicable to a CSI collecting process.