Complex exponential

[AliSabra]

Hello guys,

I want to multiply a signal by a complex exponential just as in the second picture. Is it correct the way I did it ? See the first picture below

The idea is to multiply a signal by a two ray channel (second pic). Is it correct to multiply a complex signal with the Doppler shift this way ?

Best regards,

Ali Sabra

[wiebe@CARYA]

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@AliSabra wrote:

Hello guys,

I want to multiply a signal by a complex exponential just as in the second picture. Is it correct the way I did it ? See the first picture below

The idea is to multiply a signal by a two ray channel (second pic). Is it correct to multiply a complex signal with the Doppler shift this way ?

Best regards,

Ali Sabra

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It seems OK to me.

You can test by putting it in a for loop, or applying the formula to a ramp. That should give an output of a sin in Im and a cos in Re (or vice versa).

[AliSabra]

Thanks for your help.

Am I testing it correctly ?

Because there is no difference between the original signal and the Doppler shifted one.

Maybe because I am using a waveform generator instead of a simulated signal ? I dont see the I and Q 

[wiebe@CARYA]

You're multiplying a single value (scalar) with a signal.

You should be multiplying a signal (the original) with the generated signal (a ramp put through the formula).

Both are functions or time, you now only have one function as time.

[wiebe@CARYA]

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@AliSabra wrote:

I dont see the I and Q 

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To see the I and Q, you'd need to split the signal up into the Im and Re of the result...

[AliSabra]

Can you send me a screenshot plz ? 

[wiebe@CARYA · Accepted solution]

Sure, but it's LV CG:

It's clear that multiplying the signals, adds the frequencies.

[AliSabra]

Look what is happening :S

[AliSabra]

Maybe the configuration isn't correct ?

[wiebe@CARYA]

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@AliSabra wrote:

Maybe the configuration isn't correct ?

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I'm not into NXG enough to adive on that...

Apparently, those signals do work with complex numbers, but the ramp signal seems to be different than the sine?