The slides illustrate and visualize the design of a simple LIFI application-underwater communication. Using some pre-programmed module with the aim of understanding the concept of VLC visible light communication. Read full preprint: https://www.researchgate.net/publication/348294258_Conceptual_Design_of_LiFi_Audio_Transmission_Using_Pre-Programmed_Modules

1. Audio
Transmissionusing
LED
A low cost illustration of
Application of Audio
Transmission using VLC.

2. The technology truly began during the
1990's in countries like Germany,
Korea, and Japan where they
discovered that LED's could be used to
send information. Harald Haas
continues to how the world with the
potential to use light for
communication.
2
LIFI
LI-FI is transmission of data through a LED light bulb
that varies intensity faster than human eye can follow
History

3. 3
HOW LI-FI WORKS
• Operational procedure is very simple, if the
LED is on, you transmit a digit ‘1’, or data is
transmitted if it is off you transmit a ‘0’ and data
is not transmitted
• The LEDs can be switched on and off very
quickly, which gives nice opportunities for
transmitting data.
• Hence all that required is some LEDS and a
controller that code data into those LEDs.

4. 4
BLOCK DIAGRAM
The driving circuit consists of a control circuit and output
stage to modify the data and make it ready to be sent.
The receiving circuit consists of a filter to select the
required band, amplification stage to provide the required
Signal to Noise ratio in order to demodulate the signal.
Usually, we add to these components some necessary
circuits like a driving circuit and a receiving circuit.

5. LIFI Application
Using pre-programmable modules to illustrate the
application of LIFI Underwater Communications
5

6. 6
Using RF signals is impractical due to strong signal
absorption in water. Li-Fi provides a solution for short-
range communications.
Submarines could use their headlamps to
communicate with each other, process data
autonomously and send their findings
periodically back to the surface in Underwater
Remotely Operated Vehicles (ROV).
Another important issue is that Li-Fi can even
work underwater where Wi-Fi fails
completely, thereby it's open for military
operations
UNDERWATER
COMMUNICATIONS

7. WHAT YOU NEED7
Photo diodeLight source
We used the light source as
our transmission source.
we use the solar panel as
receiving module
speaker
We use one speaker to output
the receiving signals
amplifier
We used PAM8403 as our
audio amplifier.
AUX
we use an auxiliary cable (AUX) as a
communications cable.

8. LIFI TRANSMITTER
8

9. In the transmission section there is a LED, a
battery and an auxiliary cable (AUX) for audio
transmission
9
TRANSMISSION
SECTION
The AUX also known as audio jack receive signals form
device and transfer analogue audio signals to the LED.
In which drives the LED using on-off-keying (OOK)
Modulation. If the LED is on, it transmits a digital 1
otherwise it transmits a digital 0.
The LEDs is switched on and off quickly to transmit data
that can't be detected by a human eye.

10. o From the diagram 1 and 2 are power
input.
o 3 and 4 are for communication
(transmission).
o 2 and 4 are USB Port and AUX port.
o 1 and 3 are alternative of 2 and 4.
10
Description:
Bluetooth voice player. It support Bluetooth wireless
connections. Smart home playback
Amplifier Module 1

11. Using AUX communication cable and USB
cable as power source.
11
1

12. Directly connecting the modules.
12
2

13. 13
Transmitter Module

14. LIFI RECEIVER
14

15. On the receiver section there is a solar panel, which
convert this light into electric signals and it will
pass the electric signals to the PAM8403 audio
amplifier.
15
RECEIVER
SECTION
The photo detector in this case the solar panel
absolved the ones and zeros from the LED source
This signals (ones and zeros) are demodulated and
amplified by the audio amplifier.
The light intensity is absorbed by solar panel then
the audio signal come out using a speaker.

16. 16
Description:
The PAM8403 is a 3W, class-D audio amplifier. It offers low
THD+N, allowing it to achieve high-quality sound reproduction
Amplifier Module 2
o 3W Output at 10% THD with a 4Ω Load and 5V
Power Supply
o Filter less, Low Quiescent Current and Low EMI
o Low THD+N
o Superior Low Noise
o Efficiency up to 90%
o Short Circuit Protection

17. 17
RECEIVER CIRCUIT

18. 18
SUMMARY
The point of this presentation is to
illustrate and visualize the design of LIFI
application-underwater communication.
Using some pre-programmed module
with the aim of understanding the
concept of VLC visible light
communication.

19. 19
[1] Prerna Chauhan, Ritika Tripathi Jyoti Rani, "Li-Fi (Light Fidelity)-The future technology In Wireless communication," International
Journal of Applied Engineering Research, Nov 2012.
[2] M. Mutthamma, "A survey on Transmission of data through illumination - Li-Fi," International Journal of Research in Computer and,
Dec 2013.
[3] (2015) wikipedia. [Online]. http://en.wikipedia.org/wiki/Visible_light_communication
[4] Raafat Ali Ali , “Light Fidelity (Li-Fi) Technology ” Higher Institute for Applied Sciences and Technology
Communications Department 4th year, SEMINAR , April 2nd, 2015.
[5] https://www.diodes.com/assets/Datasheets/PAM8403.pdf
Reference

20. Thank You
Auwal Amshi
auwalamshi@gmail.com