D2D Communication Resource Allocation in LTE Networks

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Solution Overview

Problem

Current device-to-device (D2D) communication discovery mechanisms in LTE networks face challenges in optimizing power consumption, latency, interference, flexibility, backwards compatibility, scalability, and geographical extent, while also being limited by the need for network connection and inadequate radio link conditions.

Innovation Solution

A communication system that uses radio frames subdivided into sub-frames, where devices obtain and listen for ProSe discovery information from a base station, request resource allocation, and transmit discovery information using designated communication resources, allowing for efficient and flexible D2D communication setup.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If devices continuously monitor for discovery signals to enable fast D2D discovery, then discovery latency is reduced, but power consumption increases

Engineering Contradiction:
Improvediscovery latencyVSAvoidpower consumption
Core Design Contradiction:
Loss of timeVSUse of energy by moving object

Solution Approach 1:

The system implements periodic discovery signal transmission where devices transmit discovery signals at specific intervals rather than continuously. The base station configures discovery resource pools with periodic time-frequency resources, allowing devices to enter low-power states between discovery periods while maintaining acceptable discovery latency through optimized periodic monitoring.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The base station pre-allocates discovery resources and configures discovery signal parameters before devices need to perform discovery. This preliminary configuration includes setting up discovery resource pools, transmission periodicity, and power control parameters, enabling devices to efficiently execute discovery without continuous network interaction or excessive power consumption.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If discovery resources are allocated on a non-UE specific basis to simplify resource management, then device complexity is reduced, but interference and contention increase

Engineering Contradiction:
Improveresource management complexityVSAvoidinterference and contention
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The system implements a hybrid resource allocation approach where discovery resources are allocated based on local conditions. The base station assigns specific time-frequency resources to individual UEs within discovery resource pools, considering local interference conditions, UE capabilities, and traffic patterns. This localized resource quality assignment reduces contention while maintaining manageable complexity through base station coordination.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Discovery resource allocation is made dynamic rather than static. The base station can reconfigure discovery resource pools, adjust transmission periodicity, and reallocate resources based on changing network conditions, UE density, and interference levels. This dynamic adaptation balances resource management complexity with interference mitigation.

Inventive Principle:
Principle #15Dynamics

3Productivity

If discovery mechanisms are optimized for specific scenarios to achieve high performance, then discovery efficiency is improved, but adaptability to varying information transmission needs deteriorates

Engineering Contradiction:
Improvediscovery efficiencyVSAvoidflexibility for varying information needs
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The discovery mechanism is designed with universal applicability through configurable discovery resource pools that can serve multiple purposes. The same discovery signal framework supports different discovery types (Type 1 and Type 2), various information transmission needs, and different service scenarios. Parameters such as resource periodicity, frequency allocation, and signal format can be universally adjusted to match specific requirements while maintaining a unified discovery procedure.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system enables efficient adaptation through parameter configuration rather than structural changes. Key parameters including discovery signal periodicity, resource block allocation, transmission power, and signal format can be dynamically adjusted to optimize discovery efficiency for different scenarios. This parameter-based flexibility allows the same discovery mechanism to efficiently handle varying information transmission needs without redesign.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If D2D discovery is limited to network coverage areas to maintain network control, then network security and coordination are improved, but geographical extent and scalability deteriorate

Engineering Contradiction:
Improvenetwork control and securityVSAvoidgeographical extent
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The discovery mechanism is segmented into network-controlled and autonomous components. Within network coverage, the base station controls discovery resource allocation and signaling. For extended geographical areas, the system segments discovery into cell-specific and inter-cell discovery resource pools, allowing UEs to perform discovery across cell boundaries while maintaining network awareness through configured resource structures and reporting mechanisms.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2901812B1Communication system
Publication Date: 2022.05.04 NEC CORP
  • EP2901812B1 patent drawingFigure 1
  • EP2901812B1 patent drawingFigure 2
  • EP2901812B1 patent drawingFigure 3

AI summary

There is provided a communication system in which a base station controls direct device to device (D2D) communication between communication devices. The base station transmits information identifying a pattern of radio frames designated for communicating D2D signals between communication devices. When the base station receives a request for allocation of resources for transmitting D2D signals by a communication device, it transmits, to the communication device, information identifying the communication resources allocated for the D2D signals within the designated radio frames responsive to the request. The base station also transmits, for receipt by at least one other communication device in a vicinity of the requesting communication device, an indication that D2D signals are to be transmitted.