Conformal VLC Receiver Mitigating Vibration-Induced Inter-Symbol Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing Visible Light Communication (VLC) receivers face challenges due to mobility and vibrations in office settings, which cause attenuation and inter-symbol interference (ISI), limiting their communication bit rate and range.
Innovation Solution
A wide field-of-view (FOV) VLC receiver design using a photodetector array with a transimpedance amplifier, high pass filter, and wideband voltage amplifier, combined with adaptive detection algorithms like Decision Feedback Affine Projection Algorithm (DF-APA) to mitigate ISI and enhance signal reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional VLC receiver is used in mobile settings, then the receiver can detect optical signals, but mobility and vibrations cause attenuation and inter-symbol interference that limit communication bit rate and range
Solution Approach 1:
The receiver divides the optical signal detection into multiple photodetectors arranged in an array, each capturing light from different directions. This segmentation allows the system to maintain reliable signal detection across a wide field of view while supporting mobile operation, effectively resolving the contradiction between mobility and signal quality.
Solution Approach 2:
The patent implements adaptive detection algorithms that dynamically adjust to changing channel conditions caused by mobility and vibrations. The system continuously adapts its detection parameters to compensate for signal attenuation and inter-symbol interference, maintaining high communication bit rates despite dynamic environmental changes.
2Adaptability or versatility
If the receiver field of view is increased to accommodate mobility, then the receiver can track moving transmitters, but inter-symbol interference increases due to angle variations
Solution Approach 1:
The photodetector array segments the wide field of view into multiple detection zones, with each photodetector handling a specific angular range. This segmentation allows the system to maintain a wide field of view for mobility while reducing inter-symbol interference within each individual detection zone.
Solution Approach 2:
The system employs feedback mechanisms where the receiver detects angle variations and adjusts its detection parameters accordingly. This feedback loop compensates for the inter-symbol interference caused by wide-angle reception, maintaining signal integrity across the extended field of view.
3Device complexity
If standard detection methods are used, then the system is simple to implement, but the receiver cannot effectively mitigate inter-symbol interference caused by vibrations
Solution Approach 1:
The patent implements decision feedback equalization that uses previously detected symbols to compensate for inter-symbol interference in current symbols. This feedback mechanism effectively mitigates vibration-induced interference while maintaining reasonable algorithmic complexity through iterative refinement.
Solution Approach 2:
The system dynamically changes detection parameters such as integration time and filtering characteristics based on detected vibration levels and channel conditions. This adaptive parameter adjustment enables effective vibration mitigation without requiring excessively complex algorithms, balancing reliability and implementation simplicity.
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 solution enables efficient data transmission at high bit rates (up to 20 Mbps) over long ranges (7 m) with improved signal integrity and reduced dependency on spatial positions of the receiver and transmitter, effectively addressing the limitations of existing VLC systems.
Implementation Method 1
a photodetector (PD) array comprising a plurality of photodetectors to generate data-carrying photo-current in response to receiving a visible light communication
Data Source
AI summary
A mobile visible light communication (VLC) receiver and associated method of use which overcomes the detrimental effects of the time-varying inter-symbol interference (ISI) due to the VLC receiver's high acceptance angle and vibration in the structure utilizing an optimal multiple-symbol detection (MSD) module and a decision feedback affine projection algorithm (DF-APA) module.