Visible Light Positioning for Multi-User Optical Beam Tracking
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Solution Overview
Problem
Existing visible light communication (VLC) systems face challenges in establishing point-to-point communication links with multiple users at random positions, leading to poor radiation communication quality, high bit error rates, and excessive energy consumption.
Innovation Solution
A VLP-assisted multi-user optical communication system with a micro base station and user receiver, utilizing a visible light locator connected to automatic tracking optical communication devices via a serial bus, which selects the most appropriate device based on user location coordinates to establish communication links, ensuring spatial beam isolation and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LED is used for VLC transmission, then omnidirectional coverage is achieved, but optical power density is low resulting in poor communication quality
Solution Approach 1:
The system segments the coverage area into multiple zones, each served by a dedicated LD transmitter positioned to cover that specific zone. This allows each transmitter to provide focused, high-power-density coverage to its assigned users without requiring omnidirectional radiation, thus resolving the contradiction between coverage and communication quality.
Solution Approach 2:
The patent transitions from traditional 2D planar antenna arrays to a 3D spatial configuration of multiple LD transmitters positioned at different heights and angles. This three-dimensional arrangement enables precise beam steering and focusing toward users in various locations, achieving omnidirectional coverage through spatial diversity rather than omnidirectional radiation from each transmitter.
2Reliability
If LED radiated light power is increased to improve communication quality, then signal strength improves, but energy consumption becomes excessive
Solution Approach 1:
Instead of using high-power LED transmitters that radiate energy in all directions, the system employs multiple low-power LD transmitters, each providing high optical power density only in its specific coverage direction. This localized high-quality transmission approach achieves good communication quality for each user while keeping the energy consumption of each transmitter low, as each LD operates at milliwatt level rather than requiring high total radiated power.
Solution Approach 2:
The system uses multiple copies of low-power LD transmitters positioned throughout the coverage area, each serving a specific directional zone. This replicates the transmission function across multiple low-power units rather than relying on a single high-power transmitter, thereby achieving good communication quality through distributed low-power transmission that reduces overall energy consumption.
3Use of energy by moving object
If LD is used for point-to-point communication, then energy consumption is reduced, but establishing real-time links with users at random locations becomes difficult
Solution Approach 1:
The system employs dynamic beam steering capability for each LD transmitter, allowing the transmission direction to be adjusted in real-time based on user location. This dynamic adaptation enables the system to maintain optimal point-to-point communication links with users as they move randomly within the coverage area, while still using low-power LD transmitters that consume minimal energy.
Solution Approach 2:
The system uses feedback from user position information to dynamically control the beam direction of each LD transmitter. By continuously monitoring user locations and adjusting transmission directions accordingly, the system can establish and maintain real-time communication links with users at random positions while keeping each transmitter operating at low power levels.
4Productivity
If multiple users are served simultaneously, then system capacity increases, but interference between users increases
Solution Approach 1:
The system segments the service area into multiple independent zones, each served by a dedicated LD transmitter. This spatial segmentation allows multiple users to be served simultaneously in different zones without interfering with each other, as each transmitter's beam is focused on its specific zone. This resolves the contradiction by enabling multi-user service through spatial division while preventing interference through directional isolation.
Solution Approach 2:
Each LD transmitter provides high optical power density locally to its assigned zone rather than radiating uniformly in all directions. This localized transmission approach allows multiple users in different locations to receive strong signals from their respective transmitters without experiencing interference from other transmitters, thereby enabling simultaneous multi-user service with minimal interference.
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
The system effectively provides broadband transmission for multiple users with minimal interference, improving communication quality and reducing power consumption by using point-to-point communication with spatial beam isolation.
Implementation Method 1
The transmitting devices of VLC mainly use light emitting diodes (LED)
Implementation Method 2
LED usually adopts spontaneous emission mode
Implementation Method 3
The transmitting devices of VLC mainly use light emitting diodes (LED), laser diodes (LD)
Implementation Method 4
The receiving devices usually use photodiode (Positive Intrinsic-Negative (PIN))
Data Source
AI summary
A visible light positioning (VLP)-assisted multi-user optical communication system includes a micro base station and a user receiver; the micro base station includes a mounting plate, a visible light locator is provided at a middle of a bottom surface of the mounting plate, the bottom surface of the mounting plate is provided with a plurality of automatic tracking optical communication devices surrounding around the visible light locator; the visible light locator is connected to the plurality of automatic tracking optical communication devices through a serial bus; a micro base station ID and a current working status data of the automatic tracking optical communication devices are cyclically broadcast to a coverage area through the visible light locator; a user location coordinate and a user identification are sent to the visible light locator by the user receiver.