Sounding Reference Signals for UE Proximity Detection in LTE
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current LTE technology lacks efficient mechanisms for UE proximity detection near non-serving base stations, leading to inefficient resource management and potential energy wastage due to the inability to accurately determine UE presence and adjust signaling accordingly.
Innovation Solution
Implementing a method where user equipment (UE) transmits sounding reference signals (SRS) at predetermined power levels upon request, allowing base stations to detect UE proximity and adjust their operational state, such as activating or deactivating, thereby optimizing resource usage and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If base stations remain inactive to save energy, then energy consumption is reduced, but UE proximity detection capability is lost
Solution Approach 1:
The patent applies preliminary action by having UEs transmit SRS signals in advance before the base station fully activates its serving functions. This allows the base station to detect UE presence and make informed decisions about activation timing, resolving the contradiction between energy savings and detection capability.
Solution Approach 2:
The patent uses SRS (sounding reference signal) as an intermediary mechanism that enables proximity detection without requiring the base station to be in full serving mode. The SRS acts as a mediator that carries UE presence information to the base station, allowing energy-efficient operation while maintaining detection capability.
2Measurement precision
If base stations activate full signaling for all UEs, then UE proximity detection accuracy is improved, but resource management efficiency deteriorates
Solution Approach 1:
The patent applies local quality by differentiating the signaling approach based on UE proximity and needs. Close UEs receive full serving signaling while distant UEs only receive minimal SRS-based detection signaling. This selective approach improves detection accuracy for relevant UEs while maintaining resource management efficiency overall.
Solution Approach 2:
The patent uses partial action by implementing a two-tier signaling system where full serving signaling is applied only when necessary (for close UEs), while partial SRS-based detection is applied for distant UEs. This resolves the contradiction by avoiding excessive full signaling resources while maintaining sufficient detection accuracy.
3Measurement precision
If UEs transmit SRS at maximum power for detection, then base station detection sensitivity is improved, but UE energy consumption increases
Solution Approach 1:
The patent applies parameter changes by allowing flexible SRS transmit power configuration rather than fixed maximum power. The base station can adjust the required SRS power level based on distance and detection needs, enabling UEs to transmit at lower powers for distant base stations while maintaining sufficient detection sensitivity.
Data Source
AI summary
In an aspect of the disclosure, is directed to addressing UE proximity detection near non-serving base stations. Certain classes of base stations may activate and deactivate based on the presence of nearby UEs. In their deactivated state these base stations may employ no signaling or limited signaling. Networks employing such base stations may employ a discovery mechanism, as disclosed herein, to allow such base stations to detect or discover nearby UEs. In accordance with the disclosure, a UE may transmit the proximity SRS at a maximum power or another signal strength that can be determined by a listening base station. The listening base station may employ the signal to determine UE proximity and take appropriate steps, such as activating some aspects of its signaling, remaining inactive, or entering an alternative state of limited signaling or further UE detection.