Francesco Bausi

Visible light communications: real time 10 Mb/s link with a low bandwidth polymer light-emitting diode

This paper presents new experimental results on a polymer light-emitting diode based visible light communications system. For the first time we demonstrate a 10 Mb/s link based on the on-off keying data format with real time equalization on a field programmable gate array. The 10 Mb/s transmission speed is available at a bit error rate less than 4.6 × 10(-3), which is the limit for forward error correction. At a BER of 10(-6) a transmission speed of 7 Mb/s is readily achievable.

Wavelength-Multiplexed Polymer LEDs: Towards 55 Mb/s Organic Visible Light Communications

We present recent progress on visible light communication systems using polymer light-emitting diodes as the transmitters and a commercial silicon photodetector as the receiver. In this paper, we use transmitters at red, green, and blue wavelengths to investigate the maximum on-off keying link performance of each device type as the first steps toward a wavelength-division multiplexed link. We show that a total transmission speed of 13 Mb/s is achievable when considering the raw bandwidth of each of the RGB PLEDs. Such a rate represents a 30% gain over previously demonstrated systems. Further capacity improvement can be achieved using high performance artificial neural network equalizer offering a realistic prospect for transmission speeds up to 54.9 Mb/s.

A 20-Mb/s VLC link with a polymer LED and a multilayer perceptron equalizer

This letter experimentally demonstrates a visible light communication system using a 350-kHz polymer light-emitting diode operating at a total bit rate of 19 Mb/s with a bit error rate (BER) of 10-6 and 20 Mb/s at the forward error correction limit for the first time. This represents a remarkable net data rate gain of ~55 times. The modulation format adopted is ON-OFF keying in conjunction with an artificial neural network classifier implemented as an equalizer. The number of neurons used in the experiment is varied from the set N = {5, 10, 20, 30, 40} with 40 neurons offering the best performance at 19 Mb/s and the BER of 10-6.

10 Mb/s visible light transmission system using a polymer light-emitting diode with orthogonal frequency division multiplexing

We present a newly designed polymer light-emitting diode with a bandwidth of ~350  kHz for high-speed visible light communications. Using this new polymer light-emitting diode as a transmitter, we have achieved a record transmission speed of 10  Mb/s for a polymer light-emitting diode-based optical communication system with an orthogonal frequency division multiplexing technique, matching the performance of single carrier formats using multitap equalization. For achieving such a high data-rate, a power pre-emphasis technique was adopted.

A 10 Mb/s visible light communication system using a low bandwidth polymer light-emitting diode

In this paper we experimentally demonstrate a 10 Mb/s error free visible light communications (VLC) system using polymer light-emitting diodes (PLEDs) for the first time. The PLED under test is a blue emitter with ~600 kHz bandwidth. Having such a low bandwidth means the introduction of an intersymbol interference (ISI) induced penalty at higher transmission speeds and thus the requirement for an equalizer. In this work we improve on previous literature by implementing a decision feedback equalizer, rather than a linear equalizer. Considering 7% and 20% forward error correction codes, transmission speeds up to ~12 Mb/s can be supported.

Organic visible light communications: Recent progress

The field of organic visible light communications is rapidly gaining interest in the research community as a standalone technology in optical wireless communications. Organic small molecule and polymer photonic devices are the focus of wide ranging research due to fascinating characteristics such as mechanical flexibility and extremely low cost solution based processing. On the other hand, charge transport mobility in organic semiconductors is orders of magnitude lower than in inorganics, resulting in corresponding bandwidth limitations and generating a major challenge for increasing transmission speeds. Recently, however, data rates have been demonstrated at Ethernet speeds (10 Mb/s) for the first time. In order to reach such transmission speeds we reported several substantial steps of progress in the literature which will be reviewed in this work.