D2D Resource Allocation and Power Control in LTE

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Solution Overview

Problem

Existing technologies have not adequately addressed the efficient performance of Device-to-Device (D2D) communication in LTE systems, particularly in terms of resource allocation and power control for D2D services.

Innovation Solution

A terminal device and communication method that utilize cell aggregation, multiple resource allocation modes, and advanced power control mechanisms to optimize D2D communication, including the use of specific physical channels and signals like PD2DSCH, PD2DDCH, D2DSS, and D2DRS, with dynamic configuration of CP lengths and transmit powers based on higher layer signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If D2D communication is implemented in LTE systems, then new communication capabilities are provided, but resource allocation and power control complexities increase

Engineering Contradiction:
ImproveD2D communication capabilityVSAvoidresource allocation and power control
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments D2D resource allocation into multiple modes (Mode 1 with base station control, Mode 2 with autonomous selection) to handle different scenarios. This segmentation allows the system to choose appropriate complexity levels based on specific D2D communication requirements, reducing overall system complexity while maintaining versatility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic power control mechanisms where transmit power is adjusted based on path loss measurements, power control parameters received from base stations, and real-time communication conditions. This dynamic adjustment optimizes power usage while managing interference, addressing the complexity of power control in D2D systems.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If multiple resource allocation modes are used for D2D communication, then resource allocation flexibility is improved, but processing complexity increases

Engineering Contradiction:
Improveresource allocation flexibilityVSAvoidprocessing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent employs dynamic resource allocation where the terminal can switch between Mode 1 (base station scheduled) and Mode 2 (autonomous selection from pre-configured pools) based on network conditions and service requirements. This dynamic approach provides flexibility while managing processing complexity through clear mode selection criteria.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes resource allocation parameters dynamically by configuring different resource pools for different D2D services and adjusting power control parameters based on path loss and interference conditions. This allows flexible resource allocation while keeping processing manageable through parameter-based control rather than complex algorithms.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If transmit power is increased for D2D signals, then communication reliability is improved, but interference to cellular communication increases

Engineering Contradiction:
ImproveD2D communication reliabilityVSAvoidinterference to cellular communication
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent implements feedback-based power control where terminals measure path loss to the base station, receive power control parameters (P0, alpha, TPC commands) from the network, and adjust transmit power accordingly. This feedback mechanism ensures D2D signals maintain sufficient power for reliable communication while preventing excessive interference to cellular users.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes transmit power parameters dynamically based on communication conditions, using different power control parameter sets for different D2D services and adjusting power levels according to measured path loss and network instructions. This allows reliable D2D communication at appropriate power levels without causing harmful interference.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If D2D resources are allocated from cellular resources, then resource utilization efficiency is improved, but interference management becomes more difficult

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidinterference management
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments cellular resources into dedicated D2D resource pools configured by the base station, separating D2D and cellular resource usage in time and frequency domains. This segmentation improves resource utilization by enabling simultaneous D2D and cellular operations while simplifying interference management through resource isolation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The base station acts as an intermediary that configures and manages D2D resource pools, coordinating between cellular and D2D resource usage. This intermediary control enables efficient resource utilization while managing interference through centralized resource allocation and power control parameter configuration.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3177084B1Terminal device, base station device, communications method and integrated circuit
Publication Date: 2019.05.01 SHARP KK
  • EP3177084B1 patent drawingFigure 1
  • EP3177084B1 patent drawingFigure 2
  • EP3177084B1 patent drawingFigure 3

AI summary

A first resource for transmission of first information is configured, a second resource for transmission of second information is configured, a third resource for transmission of a first synchronization signal and transmission of third information for indicating a frame number is configured, a fourth resource for transmission of a second synchronization signal and transmission of fourth information for indicating a frame number is configured, and a transmit power for each of the transmission of the first synchronization signal, the transmission of the third information, the transmission of the second synchronization signal, and the transmission of the fourth information is given by using one third parameter that is configured in a higher layer and that is common to the transmission of the first synchronization signal, the transmission of the third information, the transmission of the second synchronization signal, and the transmission of the fourth information.