log-normal channel in FSO

[ahmed helmy teama]

Dear All,
Dear Damain,
If I have an simple FSO communication as attached, how can i call matlab program to establish log-normal channel in free space optical communication using optiwave 7.
note. the matlab code for log-normal distribution is
x=normrnd(a,b,c,d);
a=mean b=standard deviation c=number of rows d=number of columns
y=exp(2*x); y:log-normal random variables
Hope your support.
Regards,
Ahmed

[Abhishek Shrama]

for example of how to co simulate matlab with optisystem there are a lot many examples on forum and in samples as well.
try looking for videos for setting up components using matlab.
For example have a look at:

Matlab Binary Switch

[alistu]

There Are a lot of examples regarding the co-simulation between Matlab and OptiSystem, but unfortunately all of them just give the main idea of what happens and do not save you a lot of time on learning how to do the cosimulation when it is more complicated than what is shown in the example.
To put it simply, the output and input to the channel are vectors. So first you should be able to know how to observe them and then, try to make a program that makes the changes on these vectors in Matlab.

[ahmed helmy teama]

Thanks to all but I’m just a beginner, so please anyone help me to build matlab program as below
MU=0;
SIGMA=.1;
x=NORMRND(MU,SIGMA);
y=exp(2*x); y:log-normal random variables
in the FSO optiwave as attached in the figure below
Regards,

[ahmed helmy teama]

Damian, where are you?
I need your help please.

[Damian Marek]

Ahmed,

I’m back in the office this week after giving an Optiwave training in Korea last week! As for your question, I can help you get your Matlab program working with the Matlab component in OptiSystem, but unfortunately I do not have the resources to build a Matlab program from scratch for you.

If you have a m-file and project file you want to get working together please attach them and I will help you out! If you have any specific questions about how the interface between the two difference products works I can also help you there.

Regards

[ahmed helmy teama]

Damian,
Thank you so much. Have a nice tripe.
I will attach a Matlab program.
Thanks again for your concern.
Regards

[ahmed helmy teama]

Dear Damian,
Kindly fine the attached files(osd and m file) herewith our simulation that doesn’t work
thank you
yours,

[Damian Marek]

Here I fixed the m-file. I believe you wanted to multiply the entire vector by different random numbers so I used the .* operator instead.

Your Matlab component also did not correctly call the function aaa, so I changed the initial command.

Cheers

[ahmed helmy teama]

Dear Damian,
Are You find the attachment, kindly i need your advice.
Thanks

[Damian Marek]

Yes I found the attachment thank you. This is the next item I am looking at.

[ahmed helmy teama]

Thanks Damian, but i can’t open the osd file, could you please send it to me via my my e-mail(ahmed.teama@te.eg)
yours,

[Damian Marek]

Unfortunately, since you have an older version of OptiSystem you will not be able to open the file. You should be able to use your original project file but make these changes:

1) Change the run command to “aaa;” which is the name of the file and also switch back the Matlab search path to where you can find the file.

2)For some reason the Optical Receiver that came placed in your file was giving me an error so I just deleted it and placed a new one and it worked fine, maybe you changed some parameters? I also changed the Bit rate of the Bit Sequence Generator to scripting mode and used the global parameter Bit rate to control the value, which is the default option.

Regards

[Naazira Badar]

Hi all..

This post was really beneficial for me, as I am also working on FSO and I want to simulate my system on various Turbulence fading models.
Could you please tell me can I use the code you have provided above for any link range and any modulation scheme that I employ in my system??

Regards.

[aasif bashir dar]

hi damain sir,
i have the confusion that the .osd screen shot that ahmad helmy has attached shows the matlab block outside the FSO, but we have apply these fading models inside the FSO.
how could we apply such design to practical application.

with regards

[Naazira Badar]

Hi Aasif..
Well, that option, i.e. the scintillation index inside the FSO channel component properties could be disabled.
Then the MATLAB component could be placed. Hope this helps you understand.

Regards.

[aasif bashir dar]

hi naazira,
are you confident about that such design will be useful for practical scernario.
because in environment sometimes many factors interact together to effect the signal transmission.

its like you are applyinf superposition in such design.
hope you will reply soon.

with regards

[Naazira Badar]

Hi Aasif.

Use of the MATLAB component should not be confused with the practical implication.I believe use of a MATLAB compomponent is just intended to add an additional turbulence model here.What we logically did is : Disable one model and enable the other one.That should not alter the practical scenario. Hope I was clear enough.

Regards.

[Naazira Badar]

Hi Damian and Ahmed..

Is the code logically right?
I mean x= normrnd(mu,sigma) generates normal distributin variables. How does the expression exp(2*x) change it to log-normal?
Also, why didn’t you directly use the function lognrnd? Kindly helpme understand it.

Regards.

[Author]

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