D2D Communication Signaling via eNB Resource Allocation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current LTE networks face challenges in efficiently managing device-to-device (D2D) communications within the same licensed band, requiring significant changes to the LTE architecture and control signaling structure to facilitate direct communication between user equipment (UEs) while maintaining network control and resource allocation.
Innovation Solution
Implementing a centralized system where the evolved Node B (eNB) allocates and manages time-frequency resources for D2D communications, initiating and permitting D2D links between suitable UEs, with control signaling primarily originating from the eNB to minimize architectural changes and allow for direct control signaling between D2D pairs once established.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If D2D communications are implemented within the LTE licensed band, then spatial reuse and system throughput are improved, but significant changes to the LTE architecture and control signaling structure are required
Solution Approach 1:
The patent introduces a centralized system (eNB or designated UE) as an intermediary to manage D2D communications. This intermediary handles resource allocation, link establishment, and control signaling, thereby enabling D2D communications without requiring fundamental changes to the LTE architecture. The intermediary mediates between the direct D2D links and the core network, maintaining architectural integrity while enabling new functionality.
Solution Approach 2:
The patent enables the existing LTE infrastructure to serve multiple functions: traditional cellular communications and D2D communications. By allowing UEs to operate in both cellular mode and D2D mode, and by using the same licensed band for both purposes, the system achieves multi-functionality without requiring separate dedicated infrastructure for D2D communications.
2Reliability
If centralized control is maintained for D2D communications, then network control and resource allocation are preserved, but control signaling overhead increases
Solution Approach 1:
The patent extracts certain control functions from the centralized eNB and transfers them to the D2D UEs themselves. For example, once resources are allocated by the eNB, the actual data transmission, HARQ acknowledgments, and power control adjustments are handled directly between UEs without continuous eNB intervention. This extraction reduces the control signaling overhead while maintaining essential network control.
Solution Approach 2:
The patent segments the control signaling into different layers: high-level resource allocation and admission control remain centralized at the eNB, while lower-level transmission control, power adjustment, and HARQ operations are decentralized to the UE pair. This segmentation allows the system to maintain reliability through centralized oversight while reducing overhead by localizing routine control functions.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Described are methods and devices for enabling D2D communications with signal structures that require minimal changes to the current LTE architecture. In the embodiments described, the eNB grants resources to UEs for D2D communication and either initiates or permits a pair of UEs to establish a D2D link. Certain embodiments are designed to minimize changes to the current LTE control signaling structure by having the control signaling always come from the eNB as in a normal cellular link so that the transmitting UE transmits over a data channel (e.g., PUSCH/PDSCH) that the receiving UE is able to decode.