D2D Cellular Transmission Power Imbalance Mitigation

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Solution Overview

Problem

In network-assisted device-to-device (D2D) communication, simultaneous transmission to both a network node and a peer device can lead to significant power imbalances, causing adjacent channel interference (ACI) and degrading transmission quality due to the need for different transmission power levels between D2D and cellular links.

Innovation Solution

A radio frequency communication device and network node are equipped with a controller to detect power imbalances and apply mitigation techniques such as prioritizing transmissions, adjusting transmission power, or restricting data links to minimize interference, ensuring robust simultaneous D2D and cellular transmissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If simultaneous transmission to network node and peer device is performed, then spectrum utilization and resource efficiency are improved, but transmission power imbalance causes adjacent channel interference and degrades transmission quality

Engineering Contradiction:
Improvespectrum utilizationVSAvoidtransmission quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent dynamically adjusts transmission parameters including power spectral density (PSD) levels, modulation and coding schemes (MCS), and resource block allocations based on real-time channel conditions and interference measurements. The network node configures different PSD values for D2D and cellular transmissions, and adjusts these parameters adaptively to maintain transmission quality while enabling simultaneous transmissions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system implements dynamic resource allocation where the network node continuously monitors transmission conditions and reconfigures resource assignments for D2D and cellular transmissions. Transmission power levels, resource block assignments, and MCS indices are adjusted in real-time based on channel state information and interference measurements, allowing the system to adapt to changing conditions while maintaining both simultaneous transmissions.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If different transmission power levels are used for D2D and cellular links, then communication requirements are met, but power imbalance generates adjacent channel interference

Engineering Contradiction:
Improvecommunication flexibilityVSAvoidadjacent channel interference
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the potentially harmful power imbalance into a manageable parameter by introducing power spectral density (PSD) configuration where the network node explicitly sets different PSD values for D2D and cellular transmissions. By carefully controlling PSD ratios and using PSD-based resource allocation, the system transforms the power difference from a source of interference into a controllable parameter that can be optimized for both communication requirements and interference mitigation.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The network node acts as an intermediary that mediates between D2D and cellular transmissions by configuring resource allocations, power levels, and transmission parameters. The network node receives interference measurements from user equipment and adjusts resource assignments accordingly, serving as a controlling intermediary that balances the needs of both communication types while minimizing their mutual interference.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Quantity of substance

If non-orthogonal resource sharing is implemented, then resource utilization increases, but intra-cell interference increases

Engineering Contradiction:
Improveresource utilizationVSAvoidintra-cell interference
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent segments the available spectrum resources into different resource blocks and assigns them orthogonally or near-orthogonally to D2D and cellular transmissions. By dividing the frequency spectrum into discrete resource blocks and carefully managing their allocation, the system enables multiple simultaneous transmissions while controlling interference through structured resource partitioning rather than completely random or overlapping assignments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes key transmission parameters including power spectral density, modulation order, and coding rate based on the specific resource allocation. The network node configures different PSD values for different resource blocks, adjusts MCS indices according to channel conditions, and optimizes these parameters to maximize resource utilization while keeping interference within acceptable thresholds.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2995155B1Improved handling of simultaneous network communication transmission and d2d communication transmission
Publication Date: 2019.02.20 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD
  • EP2995155B1 patent drawingFigure 1~3
  • EP2995155B1 patent drawingFigure 4~5
  • EP2995155B1 patent drawingFigure 6A~6B

AI summary

A radio frequency communication device (100) comprising a radio frequency communications interface (130) and a controller (110), wherein said controller (110) is configured to establish network communication with a network node (310) and to establish device-to-device communication with a second radio frequency communication device (325) via said radio frequency communication interface (130). The controller is further configured to determine whether there is to be performed a simultaneous transmission comprising a network transmission over said network communication with said network node (310) and a D2D transmission over said device- to-device communication with said second radio frequency communication device (325); determine if there is a transmission problem related to said simultaneous transmission; and if so determine a mitigation technique; and perform said network transmission and said D2D transmission according to said mitigation technique to mitigate said transmission problem.