Visible Light Communication (VLC)

[VLC]

Visible Light Communication

Contact Information

University: The University ofTexas At Austin

Team Member(s): Andre Esteva,Jackson Massey, Blake Levy, Kelly Cook

Faculty Advisors: Robert Heath

Ph.D Advisor: Kien Truong

Email Address: andre.esteva@gmail.com  jackson.massey@gmail.com blakelev4589@gmail.com kellylicook@gmail.com truongkien@gmail.com rheath@ece.utexas.edu

Description:

Introducing VLC systems to existing LED lighting has very interesting and novel applications. The high frequency ofvisible light implies a large bandwidth and very fast data transmission. We could thus use VLC to obtain high-speed internet from indoor overhead lighting or to implement traffic control systems using the LEDs in standard stop-lights.The fact that VLC requires line-of-sight transmission makes it a very secure means of transmission, leading to security and military applications. Also, the use of LEDs means that VLC uses very little power and is harmless to humans, making it a very safe and energy-efficient system. VLC improves on many existing wireless communications issues, including frequency band congestion, lower data transmission, and insecurity of transmission.

Products:

Hardware

     NI-PXI Chassis

     9 LEDs

      PIN Photodiode

     Amplifying circuit

Software

      NI Labview

The Challenge:

Uni-directional communication

Increased transmission distance (~6-9ft) with standard indoor lighting creating optical noise

Allowing for varied angles of incidence

Implementing multiple modulation schemes

Low bit-error-rate

Transmitting a picture

The Solution

Our team created a receiver-transmitter wireless system that uses visible light as the carrier frequency. Our transmitter is a 3x3 LED Array set into a standard desk lamp, and our receiver is a photodiode with an amplifying circuit. We have successfully transmitted random information, a string, as well as a picture. Our system takes information, modulates and processes it using Labview, transmits it across free space using the desk lamp, then receives, demodulates, and decodes it at the receiver end.

The 3x3 LED Array greatly improved both the transmission distance and permittable angle of incidence. The added brightness helped overcome the severe optical noise that is the result of standard indoor lighting. Furthermore, we added a second stage to the amplifying circuit in order to boost the gain and decrease the noise, leading to a lower bit error rate.

Benefits gained using Labview and NI Hardware

The NI-PXI proved to be very useful in converting a digital signal to an analog voltage. Given a digital waveform it has the processing capabilities to output this as a waveform to a wire, and thus, to our LED array. Had we implemented this on our own, we would have added a whole new level of complexity to our system, and likely introduced a new degree of error. Furthermore, the integration of labview with the PXI, and the fact that labview has many signal processing tools made it a natural choice of software to use in our system.

OVERVIEW:

SOFTWARE:

HARDWARE:

[jcallaway]

Hi Andre, Jackson, Blake, and Kelly,

Thank you so much for your project submission into the NI LabVIEW StudentDesign Competition. It's great to see your enthusiasm for NI LabVIEW! Make sureyou share your project URL(https://decibel.ni.com/content/docs/DOC-16435)with your peers and faculty so you can collect votes for your project and win.Collecting the most "likes" gives you the opportunity to win cashprizes for your project submission. If you or your friends have any questionsabout how to go about "voting" for your project, tell them to readthis brief document (https://decibel.ni.com/content/docs/DOC-16409).

Finally - please add the following information to your submission document(so it can be considered complete). I know that parrts of the information weneed are in your attachment, but we need it completed to fully process your2011 LabVIEW Student Design Project Submission.

Products:(hardware, software, modules, and toolkits)

The Challenge and The Solution:

Benefits gained using LabVIEW and NI tools

Good luck,

Jessica in Austin, Texas

[BassamMohamed]

Hi Andre, Jackson, Blake, and Kelly, 

It is a very nice work and I wish you all the best. 

I will appreciate if you can clarify why did you used a carrier frequency at 50 KHz while VLC should not have any carrier (base band to Light freq band directly). 

regards, 

Bassam