How to simulate thermal noise altering a signal at various sample rates?

Tried a few methods.

It is is not possible to set the sample rate in the ADC block from Simulink, so instead of the wave form generator block, a discretized sine wave is generated using the sine wave block of the DSP signal toolbox. It is clear how to set the sample rate of this sine wave in code using the SampleRate property, but not sure how to do it via the dialog box after clicking on the block. There is a "sample time" option.

The thermal noise block from the comminications toolbox does not allow to set a sample rate via the GUI. Via GUI and code both it cannot be connected to the sine wave function or block from the DSP signal toolbox.

The error is:

"Error using comm.internal.AWGNChannelBase/validateInputsImpl

Expected signal input to be one of these types:

double, single, embedded.fi"

A simulation is required for the below or equivalent:

An analog signal source => thermal noise source => anti-aliasing filter => ADC with adjustable sample rate =>output to display/further processing

[recent works]

It seems like you are facing issues with configuring the sample rate for certain blocks in Simulink and connecting blocks from different toolboxes due to compatibility issues. Can I suggest some general steps may useful

[user123]

@recent works Yes, that could help.

Answer 1

[Shivam Lahoti]

Hi user123,

As per my understanding, you want to run a simulation where the workflow involves various analog and digital blocks. In the workflow, you want to simulate thermal noise and for that, you used the receiver thermal noise block from the communication toolbox and encountered an error.

The error might arise from a compatibility issue between blocks from different toolboxes. In your case, the error message suggests that the thermal noise block expects a signal input of type double, single, or embedded.fi.

Along with this, I found another way to design thermal noise. Have a look at the following documentation.

https://in.mathworks.com/help/comm/ref/comm.thermalnoise-system-object.html

Have a look at the example section to understand how you can generate the thermal noise at a particular sample rate. Or else run the following code to refer to the example.

openExample('comm/AddThermalNoiseToQPSKSignalExample') 

I hope this helps.

Regards,

Shivam Lahoti.