MulteFire Discovery Signal Sparse Periodicity for Wi-Fi Interference

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Solution Overview

Problem

Current wireless communication systems, particularly in unlicensed spectrum like 5G NR, face challenges in minimizing interference with Wi-Fi networks due to inadequate coexistence mechanisms, leading to potential disruptions in shared unlicensed bands.

Innovation Solution

The implementation of MulteFire technology, which operates solely in unlicensed spectrum without a licensed anchor, uses sparse periodicity for discovery signals and Listen Before Talk (LBT) methods to minimize interference, ensuring coexistence with Wi-Fi by autonomously deciding transmission based on neighboring Wi-Fi activity and adhering to regulatory detection thresholds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If MulteFire uses dense periodicity for discovery signals to improve network visibility and connection establishment, then network discoverability is improved, but interference with Wi-Fi networks increases

Engineering Contradiction:
Improvenetwork discoverabilityVSAvoidinterference with Wi-Fi
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements sparse periodic transmission of discovery signals at predetermined intervals rather than continuous transmission. This periodic action allows the system to maintain network discoverability while reducing overall interference levels in the unlicensed spectrum by being present only when necessary for network establishment.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts transmission behavior based on LBT outcomes and channel conditions. When the channel is clear, discovery signals are transmitted according to sparse periodicity; when Wi-Fi activity is detected, transmissions are deferred. This dynamic adaptation resolves the contradiction between maintaining discoverability and avoiding interference.

Inventive Principle:
Principle #15Dynamics

2Duration of action of stationary object

If MulteFire transmits continuously to maintain network availability and service quality, then service continuity is improved, but interference with Wi-Fi networks increases

Engineering Contradiction:
Improveservice continuityVSAvoidinterference with Wi-Fi
Core Design Contradiction:
Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The system employs LBT mechanisms that continuously monitor the channel for Wi-Fi activity and provide feedback to control transmission decisions. This feedback loop enables the system to maintain service continuity by transmitting when the channel is clear while avoiding interference by deferring transmissions when Wi-Fi is detected, thus resolving the contradiction between continuous service and interference avoidance.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary channel assessment through LBT before initiating transmissions. By detecting Wi-Fi activity in advance and preemptively avoiding transmission during occupied periods, the system prevents interference before it occurs while maintaining service continuity through timely transmission when channels are available.

Inventive Principle:
Principle #9Preliminary anti-action

3Area of stationary object

If MulteFire increases transmission power to improve signal coverage and penetration, then coverage area is improved, but interference with Wi-Fi networks increases

Engineering Contradiction:
Improvecoverage areaVSAvoidinterference with Wi-Fi
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The system dynamically changes transmission parameters including power levels based on LBT outcomes and channel conditions. When Wi-Fi activity is detected, transmission power is reduced or transmissions are deferred entirely. This parameter adaptation allows the system to achieve adequate coverage when channels are clear while minimizing interference with Wi-Fi networks, resolving the contradiction between coverage and interference.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3729897B1Resource assignment in NR-ss
Publication Date: 2024.09.18 QUALCOMM INC
  • EP3729897B1 patent drawingFigure 1
  • EP3729897B1 patent drawingFigure 2
  • EP3729897B1 patent drawingFigure 3

AI summary

Certain aspects of the present disclosure relate to a method and apparatus for receiving a medium occupation and a resource block group (RBG) size from a gNB, wherein the radio block group size is based on a bandwidth part (BWP) configuration. In one example, UEs with smaller BWP have finer granularity in RBG size in terms of PRBs, while UEs with larger BWP may have a coarser granularity in RBG size in terms of PRBs. An additional guard band may be used if the gNB reserves some channels such that not all of the BW is occupied. For example, if the gNB reserves the 20MHz channel, it may perform better by adding additional guard band on each side of the 20MHz bandwidth to accommodate an adjacent channel leakage-power ratio (ACLR). Another aspect of the present disclosure relates to assigning a UE an interlace with equally spaced PRBs.