D2D Signal Quality Measurement Using Power Difference Estimation

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Solution Overview

Problem

In device-to-device (D2D) communication, relying solely on Device-to-Device Synchronization Signals (D2DSS) for signal quality measurement is challenging due to their intermittent availability, making it difficult for wireless devices to obtain accurate measurements for link adaptation, power control, and other Radio Resource Management (RRM) functionalities.

Innovation Solution

Measuring the power of D2D signals and determining the power difference with D2DSS, then estimating the D2DSS power to facilitate D2D operations, even when D2DSS is weak or unavailable, by combining measurements with signals having a known power relationship, such as the Physical Device-to-Device Shared Channel (PD2DSCH).

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If D2D devices rely solely on D2DSS for signal quality measurement, then measurement simplicity is maintained, but measurement accuracy deteriorates due to intermittent availability of D2DSS

Engineering Contradiction:
Improvesignal quality measurement accuracyVSAvoidmeasurement availability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent combines measurements from multiple signal sources (D2DSS and other D2D signals such as discovery signals and communication signals) to estimate signal quality. When D2DSS is unavailable, the device uses alternative D2D signals with known power relationships to D2DSS, merging these measurement sources to maintain continuous and accurate signal quality assessment for RRM functionalities.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If D2D devices use multiple signal sources for measurement, then measurement availability improves, but device complexity increases

Engineering Contradiction:
Improvemeasurement availabilityVSAvoidmeasurement processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent utilizes known parameter relationships (power differences) between D2DSS and other D2D signals to simplify the estimation process. By leveraging pre-configured power relationship parameters, the device can transform measurements from alternative signals into equivalent D2DSS measurements through straightforward parameter adjustments, avoiding complex multi-signal processing while maintaining measurement availability.

Inventive Principle:
Principle #35Parameter changes

3Extent of automation

If D2DSS transmission is restricted to specific conditions, then network control is improved, but signal availability for measurement deteriorates

Engineering Contradiction:
Improvenetwork control over D2DSSVSAvoidD2DSS availability for measurement
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The patent introduces other D2D signals as intermediary measurement sources when D2DSS is unavailable due to transmission restrictions. These alternative signals (discovery signals, communication signals) serve as mediators that maintain the measurement functionality even when network-controlled D2DSS transmission is limited, ensuring continuous RRM operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3205156B1Signal quality measurement for device-to-device communication
Publication Date: 2020.05.20 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3205156B1 patent drawingFigure 1
  • EP3205156B1 patent drawingFigure 2
  • EP3205156B1 patent drawingFigure 3

AI summary

According to some embodiments, a method in a wireless device comprises measuring power of a Device-to-Device (D2D) signal used by the wireless device for D2D operation; determining a power difference between the measured power of the D2D signal and a physical Device-to-Device Synchronization Signal (D2DSS); estimating power of a D2DSS using the measured power of the D2D signal and the determined power difference; and performing a D2D operation using the estimated power of the D2DSS.