Does Simulink Keep Memory of randomized data inputs and outputs to Blocks for processing (like Convolutional Interleaving)

openExample('comm/DigitalVideoBroadcastingTerrestrialExample','supportingFile','commdvbt.slx')

Using this as an example, we can see that there is a Random integer generator that creates 188 samples per frame. What is a frame in this instance? I'm guessing that means it outputs 188 bytes of information. Then those bytes are input into the convolutional interleaver. Then eventually the packet is modulated and demodulated and returns to its original form and compared with the initial 188 bytes.

My question is this:

Are we keeping track of every 188 bytes of information created? Is it all stored in one big array. Lets say that the block diagram is run for 1 second and does 188, 188, 188, 188, 188, 188 .... 188 (100 times). Is there a variable stored somewhere that has 18800 bytes of previous inputs and outputs? Or is the program constantly throwing away old packets and inputting new ones?

Answer 1

[Divyanshu]

Hello @Dylan Ditta,

The Random integer generator that creates 188 samples per frame, this means that it generates a vector of [188 x 1] size and lets say if the 'Sample Time' parameter of this block is '1' then it means that this block will generate a vector of [188 x 1] every 188 seconds.

You can refer the following documentation link to get more details about 'Random Integer generator':

https://www.mathworks.com/help/releases/R2022a/comm/ref/randomintegergenerator.html#fp102455_Samples_per_frame

Now regarding your second query, with respect to this example no we are not keeping track of every [118 x 1] vector because we are randomly generating the sample for each timestamp, calculating the errors using 'Error Rate Calculation' block and then discarding the sample.

Hope it helps!