Beam Switching and Reporting for Millimeter Wave Path Loss

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Solution Overview

Problem

Millimeter wave (mmW) systems experience high path loss and require directional transmission to mitigate this, necessitating beam refinement and tracking between user equipment (UE) and base stations to maintain effective communication.

Innovation Solution

The base station transmits beam reference signals in all directions for UE to identify 'coarse' beams, and then refines these with beam refinement requests to track 'fine' beams, with UE informing the base station of any changes to adjust new beams for optimal communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If directional beam transmission is used to mitigate path loss in mmW systems, then signal quality is improved, but system complexity increases due to beam refinement and tracking requirements

Engineering Contradiction:
Improvesignal qualityVSAvoidbeam refinement and tracking
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the beam management process into distinct phases: initial beam acquisition using wide beams, followed by beam refinement using narrower beams. This segmentation allows the system to first establish connectivity with coarse beams and then progressively refine to fine beams, reducing the overall complexity compared to attempting fine beam alignment from the start.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements preliminary beam acquisition using wide beams before proceeding to beam refinement. By performing this preliminary action of establishing initial connectivity with broader coverage beams, the system prepares the foundation for subsequent refined beam tracking, reducing the complexity of the overall beam management process.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If beam switching is performed to maintain coverage during UE movement, then communication reliability is improved, but beam switching delay increases

Engineering Contradiction:
Improvecoverage continuityVSAvoidbeam switching delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs preliminary identification of candidate beams during the coarse beam acquisition phase. By having potential alternative beams pre-identified and ready, the system can perform beam switching more quickly when UE movement requires handover between beams, reducing the beam switching delay while maintaining coverage continuity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where the UE reports beam quality measurements back to the base station. This feedback allows the base station to proactively identify when beam switching is needed and prepare appropriate beam transitions, reducing delays by acting on real-time channel conditions rather than waiting for connection degradation.

Inventive Principle:
Principle #23Feedback

3Productivity

If fine beam tracking is implemented to maintain optimal signal quality, then communication efficiency is improved, but measurement and tracking precision requirements increase

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidbeam tracking precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent segments beam tracking into coarse beam identification followed by fine beam refinement. This two-stage approach allows the system to first establish the general beam direction with relaxed precision requirements, then progressively refine to higher precision only when needed, reducing the overall measurement precision burden compared to continuous fine tracking.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial fine beam tracking rather than continuous full precision tracking. By performing refined beam measurements only when necessary (e.g., when coarse beam quality degrades or during specific reporting intervals), the system achieves sufficient communication efficiency without the continuous high precision measurement burden.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3465930B1System and method for beam switching and reporting
Publication Date: 2023.10.11 QUALCOMM INC
  • EP3465930B1 patent drawingFigure 1
  • EP3465930B1 patent drawingFigure 2A~2D
  • EP3465930B1 patent drawingFigure 3

AI summary

A UE may receive, from a base station, through a set of beams a set of BRSs. The UE may measure a signal quality of each BRS of the set of BRSs, and each measured signal quality may correspond to a beam of the set of beams. In an aspect, the UE may maintain a set of candidate beam indexes corresponding to a set of best measured signal qualities of the set of BRSs. In an aspect, the UE may transmit, to the base station, information indicating at least one measured signal quality and at least one beam index from the set of maintained candidate beam indexes, and the at least one beam index may correspond to the at least one measured signal quality.