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# Noise Parameter

(joined March 2015)
Participant

Hi everyone

I export a signal via Matlab block in Optiwave. Now when I Open the signal in Matlab, it is an structure variable as follows:
TypeSignal
Sampled
Sample.Signal
Sample.Time
Sample.CentralFrequency
Parameterized
Noise
Noise.Power
Noise.LowerFrequency
Noise.UpperFrequency
Noise.Phase
IndividualSample
Channels

As I checked, the length of Noise elements (like Noise.Power) is different compared to Sample.Signal.
My question is that if I want to import a variable as a signal to Optiwave, How should I assign these values (Noise Part)?

Thanks

### Responses (5):

• #19554

Hi everyone

I export a signal via Matlab block in Optiwave. Now when I Open the signal in Matlab, it is an structure variable as follows:
TypeSignal
Sampled
Sample.Signal
Sample.Time
Sample.CentralFrequency
Parameterized
Noise
Noise.Power
Noise.LowerFrequency
Noise.UpperFrequency
Noise.Phase
IndividualSample
Channels

As I checked, the length of Noise elements (like Noise.Power) is different compared to Sample.Signal.
My question is that if I want to import a variable as a signal to Optiwave, How should I assign these values (Noise Part)?

Thanks

• #19565
Damian Marek
Participant

You can either add the noise directly to the sampled signal and leave the noise bins blank, or you can keep the noise separate as a noise bin type signal.

The noise bins are a simple way to model large bandwidths of noise with a low amount of memory. Upper and lower frequency arrays determine the span of frequencies with average power given by the power array. For example, let’s say UpperFrequency[0] = 191.4 THz and LowerFrequency[0] = 191.3 THz and Power[0] = -40 dBm.

That would mean that there is a noise bin signal from 191.3 THz to 191.4 THz with power -40 dBm. The phase array will give the associated phase at that frequency range as well.

• #19568

Thank you Damian

And why the length of Noise element differs from the Sampled.Signal?

• #19570
Damian Marek
Participant

The simple answer is because it is its own signal, so it can be a different length. There is no condition that would force the noise bin data to be the same length as the sampled signal.

When the noise bins are added to the sampled signal, for example setting Convert Noise Bins to true, then during the conversion the noise bins signal will be converted to a sampled signal with the same length. I am not sure how else to explain it, but let me know if you have any questions.

Cheers!

• #19592

Thank you

Actually, I want to link the simulink to Optiwave. So I save the result of simulink a variable and use a Matlab block in Optiwave to load that variable to so a simple simulation. When I run the optiwave, it gives me the following error:

Error while calculating, component

I have upload the varaible, the error and also the circuit that I used in Optiwave.

I do appreciate it if you let me know how can I fix it.

Regards,

###### Attachments:
• #19633
Damian Marek
Participant

Without the project file its hard to troubleshoot, but it looks to me like the signal detected by the simulator at the input to the optical fiber may not be correctly set. I would go into the properties window of the first Matlab component and change the input from electrical to optical. Then you can copy the format for the output.