Reference Signal Filter Reset for CoMP Power Control

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Solution Overview

Problem

In CoMP scenarios, the existing reference signal measurement methods, particularly using CRS, lead to suboptimal uplink power control due to power imbalances and interference issues, resulting in unnecessary large UL interference and power consumption, especially in scenarios where the preferred UL serving cell does not coincide with the DL serving cell.

Innovation Solution

Implementing a method that allows for the flexible reconfiguration of reference signal filters and the use of CSI-RS for path loss measurements, enabling the UE to measure path loss to individual reception points, and resetting filter memory upon reconfiguration to improve convergence and accuracy of power control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If CRS is used for reference signal measurements in CoMP scenarios, then measurement coverage is maintained, but measurement precision deteriorates due to power imbalances and interference issues

Engineering Contradiction:
Improvemeasurement coverageVSAvoidpath loss measurement accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent segments the reference signal measurement function by introducing separate CSI-RS resources for different reception points. Instead of using a single CRS for all measurements, the system divides the measurement task into multiple independent CSI-RS measurements, each targeting a specific reception point. This segmentation eliminates interference between different transmission points and enables precise path loss measurement to individual reception points.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces CSI-RS as an intermediary reference signal between the UE and reception points. The CSI-RS serves as a dedicated measurement resource that mediates the path loss estimation process, allowing the UE to measure channel conditions without the interference that affects CRS-based measurements in CoMP scenarios.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If filter memory is not reset upon reconfiguration, then measurement continuity is maintained, but convergence speed deteriorates

Engineering Contradiction:
Improvemeasurement continuityVSAvoidpower control convergence speed
Core Design Contradiction:
Stability of the object's compositionVSSpeed

Solution Approach 1:

The patent implements dynamic filter management where the filter memory reset state is not fixed but adapts based on reconfiguration events. When reference signal parameters are reconfigured, the system dynamically resets the filter memory to accommodate new measurement conditions, while maintaining filter functionality during stable operation. This dynamic approach optimizes both convergence speed and measurement continuity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from reconfiguration events to control filter memory reset operations. When the network reconfigures reference signal parameters, this feedback triggers a filter memory reset at the UE side, ensuring that the filter adapts to new measurement conditions. This feedback mechanism coordinates between network reconfiguration and UE filter management to optimize convergence.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2781043B1Methods and arrangements for reference signal measurements
Publication Date: 2015.08.26 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2781043B1 patent drawingFigure 1
  • EP2781043B1 patent drawingFigure 2~3
  • EP2781043B1 patent drawingFigure 4

AI summary

Embodiments are disclosed which improve the accuracy of measurement quantities obtained based on filtered measurements, by enabling filter memory reset events triggered by specific configuration and/or reconfiguration commands. According to some embodiments, a method for obtaining a measurement quantity is provided. The measurement quantity is based on a filtered reference signal (RS) measurement value. The method is executed in a wireless device, e.g. a user equipment (UE). According to the method, the wireless device receives (1410) a filter reset indication. In response to the indication, the wireless device resets (1420) one or more RS measurement filters. The wireless device then obtains (1430) a new filtered RS measurement value, and obtains (1440) the measurement quantity based on the new filtered RS measurement value.