D2D SRS Mechanism for LTE Device Discovery
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Solution Overview
Problem
Current wireless communication technologies face challenges in efficient device discovery and interference management for device-to-device (D2D) communication in LTE networks, particularly in ensuring accurate discovery, minimizing signaling collisions, and scaling resource allocation for varying numbers of D2D devices.
Innovation Solution
The implementation of a sounding reference signal (SRS)-aided device discovery method, which includes cell-specific and UE-specific D2D SRS configurations, aperiodic D2D SRS triggering, and UE feedback mechanisms to enable efficient D2D communication while minimizing interference and optimizing resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If centralized control of peer discovery pilot transmission is used, then device discovery accuracy is improved, but signaling overhead and network control complexity increase
Solution Approach 1:
The patent segments the device discovery process into two parts: network-controlled SRS resource allocation and autonomous UE-based SRS transmission. The eNodeB configures SRS resources and parameters, but UEs independently transmit SRS signals for peer discovery without continuous network coordination, reducing signaling overhead while maintaining discovery accuracy
Solution Approach 2:
The network performs preliminary configuration of SRS resources, bandwidth, cyclic shifts, and other parameters before D2D communication begins. This preliminary setup enables UEs to autonomously conduct device discovery using pre-configured parameters, reducing real-time signaling requirements
2Ease of manufacture
If device discovery is performed using existing uplink resources, then resource allocation simplicity is improved, but interference with uplink communications increases
Solution Approach 1:
The patent segments resource allocation by dedicating specific SRS resources for D2D device discovery separate from regular uplink SRS transmissions. Different SRS configurations (bandwidth, frequency positions, time resources) are allocated for D2D purposes, preventing interference with normal uplink communications while maintaining resource allocation simplicity
Solution Approach 2:
The patent applies local quality by configuring cell-specific D2D SRS parameters that are optimized for D2D discovery in specific geographic areas. Different cells can have different D2D SRS configurations tailored to local interference conditions and D2D traffic patterns
3Measurement precision
If cell-specific and UE-specific D2D SRS configurations are implemented, then device discovery accuracy is improved, but signaling overhead increases
Solution Approach 1:
The patent merges cell-specific and UE-specific SRS configurations into a unified D2D SRS framework. Cell-specific parameters provide common configuration for all UEs in a cell, while UE-specific parameters provide individual customization. This merging reduces redundant signaling by establishing a hierarchical configuration structure
Solution Approach 2:
The patent implements dynamic SRS configuration where UE-specific parameters can be adjusted based on channel conditions, UE capabilities, and D2D traffic requirements. The configuration can be updated adaptively without requiring complete reconfiguration, reducing signaling overhead while maintaining discovery accuracy
Data Source
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AI summary
Technology for device discovery using a device-to-device (D2D) sounding reference signal (SRS) and device discovery using D2D SRS in a channel measurement group (CMG) is disclosed. In an example, a user equipment (UE) configured for device discovery via a node using the D2D SRS can include a transceiver module. The transceiver module can send a radio resource control (RRC) device discovery request to a node, scan D2D SRS subframes of proximity UEs using D2D SRS triggering, and send feedback to the node of detected D2D SRS information of the proximity UEs. The proximity UE can be located within a same cell as the UE.