Beamforming Resource Selection via Sensing Signals
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Solution Overview
Problem
In D2D communication, beamforming can lead to power loss and detection difficulties due to high path loss and shielding, resulting in 'hidden node' issues where user devices cannot detect each other's transmissions, causing resource collisions and restricted communication modes.
Innovation Solution
A user device employs beamforming in both a first and second frequency, using a receiving unit to receive a sensing signal in the first frequency and a control unit to select resources in the second frequency for transmission based on the sensing signal's resource location, enabling appropriate resource selection for data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If beamforming is employed in high frequency band for D2D communication, then path loss is compensated, but power loss due to shielding and detection difficulty increase
Solution Approach 1:
The patent introduces a sensing signal as an intermediary to facilitate resource selection. The sensing signal is transmitted separately from the data beam, allowing receiving devices to detect resource usage without needing to detect the main data beam directly. This intermediary signal enables hidden nodes to identify occupied resources and avoid collisions.
2Power
If beamforming with narrow beam width is used to compensate path loss, then transmission power efficiency improves, but resource collision and hidden node problems occur
Solution Approach 1:
The patent implements preliminary sensing before actual data transmission. Devices transmit sensing signals in advance to announce their intended resource usage, and other devices can detect these signals to avoid selecting the same resources. This preliminary action prevents resource collisions before they occur.
Solution Approach 2:
The sensing mechanism provides feedback information about resource occupancy to all devices in the network. By monitoring sensing signals from other devices, each device gains knowledge about which resources are currently in use, enabling informed resource selection decisions that prevent collisions.
3Length of stationary object
If beamforming is used in D2D communication, then communication range is extended, but communication mode is restricted to half-duplex
Solution Approach 1:
The patent segments the communication process into separate sensing phase and data transmission phase. During the sensing phase, devices transmit sensing signals to detect resource usage. This time-division approach allows devices to alternate between transmitting and receiving, enabling full-duplex operation while maintaining beamforming benefits for extended range.
Data Source
AI summary
A user device performing communication with another user device by beamforming in a first frequency and a second frequency different from the first frequency is provided. The user device includes a receiving unit configured to receive a first sensing signal in the first frequency; a control unit configured to select a resource in the second frequency used for transmission, based on a resource location on a radio frame in which the first sensing signal is provided, or based on information, contained in the first sensing signal, indicating a resource location on a radio frame in the second frequency; and a transmitting unit configured to perform data transmission in the second frequency by using the selected resource.