Abstract
Researchers at the University of Central Florida have
developed a mobile visible light communication (VLC) receiver that overcomes the
signal quality and efficiency issues that hamper the widespread use of VLC
systems. With the ability to provide secure, high-throughput indoor wireless
networking, VLCs are ideal for multi-use office environments and Li-Fi (light
fidelity) applications. However, vibrations from movements such as typing on a
laptop or handling a smartphone may cause a VLC receiver to lose efficient optical
signal reception. Such regular office activities can trigger attenuation and
impose a time-varying inter-symbol interference (ISI) on received optical signals.
Consequently, this limits the viable communication bit rate and effective range
of indoor VLC systems. As a result, existing VLC systems have limited bandwidth
and transmission bit rates (?20 Kbps) and a short communication range (?1 m).
The UCF-developed VLC receiver resolves these issues with a
design that conforms to surfaces of different IoT shapes such as laptops,
smartphones, TV monitors and virtual reality headsets. Experimental results of
a prototype VLC system showed a 20 Mbps VLC link over a 7.1 m distance with a bit
error rate of less than 10^-5. That is, a speed of 0.2 m/s,
acceleration of 43.02 m/s^2, displacement of 37.74 mm, and frequency
of 6.27 Hz. The testing included subjecting the VLC receiver body to intense
vibrations.
Stage of Development
Prototype available.
Technical Details
The invention comprises off-the-shelf-components, including a
photodetector (PD) array to generate data-carrying photo-current in response to
receiving a visible light communication; a transimpedance amplifier; a high
pass filter; and a wideband voltage amplifier. The large aggregate receiver
surface area can be a cubical design or flat structure for a wider FOV and
reception range. To overcome the detrimental effects of time-varying ISI
without exponentially increasing computing time, the inventors developed an
optimal multiple-symbol detection (MSD) module and a decision feedback affine
projection algorithm (DF-AP A) module.
Benefit
Multi-element illumination and fast data communication in office environments via visible light License-free 20 MHz bandwidth, high spatial reuse potential, and low probability-of-intercept Secure and scalableMarket Application
IoT devices and light fixtures Underwater and subterranean optical wireless communication Smart city applications such as road safety systems and autonomous vehicles Asset tracking, for example, in a hospital to monitor wheelchairs and trolleys
Brochure
