Dear Moaaz,

welcome,

You need to build a transmitter and a receiver. The optical link is composed of a power LED driven by a current source and the receiver may be a photodiode or a photo transitor followed by an a linear amplifier.

As for the modulator in the transmitter you may build it by a soft ware on a computing plat form. As an example you can build the OFDM base band modulator by a matlab or simulink code or a c-code. You can use a digital signal processing to implement the OFDM base band modulator. Here you may use C-code which is more appropriate. You can implement the OFDM base band modulation by using VHDL on FPGA. After the digital modulation you need to make a dc shift to avoid clipping and then you have to convert the digital signal to analog form by using the suitable A/D converter. You need after that to amplify this signal and drive the LED current with it.

In the receiver you have to perform the inverse processes.

In summary you can build your VLC by soft ware defined radio concept.

Best wishes

thanks so much for your reply sir , i appreciate it so much.

in fact i started to search for carrying out simulation using Matlab, at the same time i started to learn the basics of the VHDL , the main problems i have now are the limited time and the design of the analog front-end of both the transmitter and the receiver , i was told that FPGAs can not generate analog OFDM base band signal , thus i am searching for circuit design schemes that can be used with the VLC applications, if you could help me i would appreciate it so much ,

thanks again for your help :)

I think the optisystem software consider a good option for simulation study.

Optsim is a good option with examples