Beam Sweeping Feedback for Longer-Range Wireless Power Transfer
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Solution Overview
Problem
Wireless communication systems face challenges in efficiently transferring power to energy harvesting UEs due to signal degradation caused by reflections or obstructions, leading to inefficient energy conversion and communication failures.
Innovation Solution
Implementing beam sweeping techniques with network entities that transmit beamformed power signals based on feedback from energy harvesting UEs, using time resources and frequency shifts for backscattering, allowing the network to adjust power levels and improve signal reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If uniform beamformed power signals are transmitted without feedback, then the network entity can simplify the transmission process, but the power transfer efficiency deteriorates due to signal degradation from reflections and obstructions
Solution Approach 1:
The patent implements feedback mechanisms where energy harvesting UEs send acknowledgments and channel state information back to the network entity. This feedback enables the network entity to adjust beamforming parameters dynamically, improving power transfer efficiency by compensating for signal degradation caused by reflections and obstructions while maintaining manageable system complexity through structured feedback protocols.
2Measurement precision
If beam sweeping is performed to detect EH UEs, then the network entity can improve the accuracy of UE detection, but the time resources required increase due to polling operations
Solution Approach 1:
The patent employs periodic beam sweeping operations where the network entity systematically transmits beamformed signals across different spatial directions at regular intervals. This periodic approach allows the network to detect EH UEs with high accuracy by monitoring backscattered signals during each sweep cycle, while the structured periodic nature prevents excessive time consumption through predictable and optimized sweep patterns.
3Loss of energy
If the network entity transmits beamformed power signals selectively based on UE quantity, then the power transfer efficiency improves, but the system complexity increases due to feedback processing requirements
Solution Approach 1:
The patent applies local quality principles by tailoring beamforming parameters specifically to each detected EH UE based on individual channel conditions and power requirements. The network entity processes feedback from each UE separately to determine optimal beamforming vectors and power levels, improving power transfer efficiency for each UE while managing system complexity through localized rather than global optimization for each transmission.
4Reliability
If frequency shifts are applied for backscattering, then the signal reception quality improves by distinguishing backscattered signals, but the device complexity at UE increases
Solution Approach 1:
The patent utilizes parameter changes by applying specific frequency shifts to backscattered signals from different EH UEs. This frequency division approach allows the network entity to distinguish and separately process signals from multiple UEs, improving signal reception quality and enabling accurate UE detection. The UE complexity remains manageable because the frequency shifting operation is a simple signal processing function that can be implemented with minimal additional hardware or computational resources at the UE side.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances the range and efficiency of wireless power transfer to energy harvesting devices by accurately determining the number of UEs and optimizing power transmission, thereby improving communication capabilities.
Implementation Method 1
Beam sweeping may involve transmitting beamformed signals to energy harvesting (EH) user equipments (UEs)
Implementation Method 2
Energy harvesting UEs, which may include passive internet of things (IOT) devices, radio frequency identification (RFID) tags, and other passive or partially passive devices, may capture and convert energy from external sources into usable power
Implementation Method 3
The network entity may transmit the beamformed powered signals
Data Source
AI summary
Methods, systems, and devices for wireless communication are described. The techniques described herein relate to beam sweeping to improve the range of wireless power transfer. An energy harvesting user equipment (UE) receives, from a network entity, an indication of a set of time resources associated with a beam sweeping transmission (e.g., polling operation) by the network entity and one or more frequency shifts associated with backscattering the beam sweeping transmission. The UE receives the beam sweeping transmission from the network entity in accordance with the set of time resources. The UE transmits a backscattered signal based on the beam sweeping transmission and the one or more frequency shifts. The UE receives, from the network entity, a beamformed power signal in accordance with transmitting the backscattered signal. The UE stores energy for powering the UE based on the beamformed power signal.