Add IQ data signal to combine with existing signal

Dear community,

I have IQ data that export from a different project (.Mat format). I have some questions regarding this.

1) Can I import IQ data into my workspace and combine it with the signal at the existing workspace?

2) Are there parameters I need to take into account? such as number of sample should be match?

My intention is to use import IQ data to combine at very close to created signal as in interference to see the impact from the interference signal.

For instance. If create QPSK signal at 1 GHz frequency. then I import BPSK signal at 1.01 GHz frequency. So expectation is to have QPSK @ 1 GHz and BPSK @1.1 GHz in the same spectrum graph.

Best Regards,

Fumihiko Sato

Answer 1

[Aishwarya Shukla]

Hi @Fumihiko Sato,

To answer your questions:

1. Yes, you can import the IQ data into your workspace and combine it with the signal at the existing workspace. To do this, you would need to load the IQ data into MATLAB using the "load" function, which will create a variable containing the IQ data. Then, you can use MATLAB functions to combine the two signals, such as adding or multiplying the signals depending on what you want to achieve.
2. Yes, there are parameters you need to take into account when combining the IQ data with the existing signal. Some of the parameters to consider are the sampling rate, the number of samples, and the center frequency of the signals. If these parameters do not match between the two signals, you may need to resample one of the signals to match the other signal's parameters before combining them. Additionally, you need to make sure that the IQ data represents a signal that is within the bandwidth of the existing signal.

Finally, I would like to clarify one point you mentioned in your question. You mentioned importing a BPSK signal at 1.01 GHz frequency to combine with a QPSK signal at 1 GHz frequency. However, BPSK and QPSK are modulation schemes, not frequencies. It is important to understand the difference between the modulation scheme and the frequency of the signal. If you want to combine two signals with different center frequencies, you would need to perform frequency shifting on one of the signals before combining them.