Path Loss Estimation via SSB Spatial Relation

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Solution Overview

Problem

Current wireless communication systems face challenges in accurately estimating path loss for uplink transmit power control due to the asynchronous nature of pathloss and spatial relation reference signals, leading to incorrect power determinations and potential waste of UE power.

Innovation Solution

The use of a synchronization signal block (SSB) in quasi-colocation (QCL) with the spatial relation reference signal allows for accurate path loss estimation, ensuring that power control is aligned with current beam conditions, thereby correcting path loss estimations and improving uplink power control accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If pathloss and spatial relation reference signals are used asynchronously for power control, then device complexity is reduced, but path loss estimation accuracy deteriorates

Engineering Contradiction:
Improvesynchronization complexityVSAvoidpath loss estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces a spatial relation reference signal as an intermediary that links the downlink beam (SSB) and uplink beam. This intermediary enables the device to determine the spatial relationship between downlink and uplink beams, allowing accurate path loss estimation for uplink transmissions by using the downlink reference signal received power (RSRP) measurements, without requiring tight synchronization between pathloss and spatial relation updates.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If path loss estimation is not aligned with current beam conditions, then power control responsiveness is improved, but transmission reliability deteriorates

Engineering Contradiction:
Improvepower control responsivenessVSAvoidtransmission reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the device measures downlink reference signal RSRP, determines spatial relation between downlink and uplink beams, estimates path loss based on these measurements, and adjusts uplink transmit power accordingly. This closed-loop feedback ensures that power control remains responsive to current beam conditions while maintaining transmission reliability through accurate path loss estimation.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4038990B1Methods and devices for facilitating path loss estimations for transmit power control
Publication Date: 2024.10.23 QUALCOMM INC
  • EP4038990B1 patent drawingFigure 1
  • EP4038990B1 patent drawingFigure 2
  • EP4038990B1 patent drawingFigure 3

AI summary

Wireless communication devices are adapted to facilitate path loss estimations utilizing a synchronization signal block (SSB). According to one example, a wireless communication device can obtain a spatial relation reference signal. The wireless communication device may determine a SSB in quasi-colocation (QCL) with the received spatial relation reference signal. A path loss may be measured utilizing the determined SSB. The wireless communication device may conduct transmit power control based on the measured path loss associated with the determined SSB. Other aspects, embodiments, and features are also included.