Sum of two signal which have differents data rate

I have two source with different sample times. I have to sum up them in the channel. When I run the simulation the following message appear on the board: "_Warning: Inconsistent sample times. Sample time ([0.0005, 0]) of signal driving input port 2 of 'channels_48_vs_48/Error Rate Calculation' differs from the expected sample time ([0.001, 0]) at this input port._"

How can I properly sum up two signal - frame based - with different sample times?

Answer 1

[Ryan G]

A rate transition should work. Sometimes Simulink will implement these automatically, but it is best practice to explicitly implement them anytime the rates change.

You can also implement sample time colors to observe the different rates in your system.

Answer 2

[Azzi Abdelmalek]

You can interpolate the two signals

Answer 3

[Giuseppe B]

the target is to sum up two signal which has different datarates. both of them are translated in frequency using a sin with a certain carrier frequency. The problem is that, if I directly sum up them, the signal with lower sample time is upsampled and so changes its bandwidth and central frequency.

The rate transition block can be used only on sample based signal, while in my case I have frame based signals.

[Ryan G]

Consider using a buffer block?

Answer 4

[Jean-Marie KERLOCH]

Hello,

I have the same issue. I want to estimate the perturbation caused by a system to another system. I've created the two signals (coding / modulation , ...) but they have two different samples rates determinated by the system parameters.

I guess the addition of the two signals must be made at the sample time of the fastest signal ? In that case, the only solution is to interpolate the signals ?

And what is the impact of an interpolation for the useful signal ?

Thanks in advance