- A visible light communication (VLC) mobile receiver for indoor environments
- Omni-directional receiver made of off-the-shelf components
- Provides a wide field-of-view (FOV) and conforms to different surfaces of the IoT (Internet of Things) shapes such as laptops, smartphones or virtual reality headsets
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/s2, 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
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.
- 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 scalable
- 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