How to generate inphase and quadrature phase of a signal?

I was trying to simply create I Q components of a signal and to recover the signal from these I Q data.

But how to create I Q? is it possible by multiplying signal with sin and cos? or by taking samples at 4 points (0,90,180,270)??

[mechetoune walid]

Google it and check this link.

https://www.markimicrowave.com/blog/top-7-ways-to-create-a-quadrature-90-phase-shift/

Answer 1

[Colin]

You might look into Hilbert transforms - Matlab function Hilbert.

From a real signal, this generates a complex signal of which the real part is the original signal, and the imaginary part is the Hilbert transform. This is essentially the original signal phase-shifted by 90 degrees

Answer 2

[Rick Rosson]

   z = x + j*y;
   v = x.*cos(2*pi*Fc*t) - y.*sin(2*pi*Fc*t);

   I = real(z);
   Q = imag(z);

[Akhil]

Hi Rick

Thank you for your response.

I'm taking a normal signal. Not the complex signal. Suppose i have a sine wave, say sin(2*pi*50*t). I need to obtain I and Q components of this signal by sampling the signal at 0 degree(Q), 90 degree(I), 180 degree(-Q) and 270 degree(-I)

[Rick Rosson]

If you have a pure sin function, then that means by definition that I = 0 and Q = -1. If that seems confusing to you, then please review the details of in-phase and quadrature.

This forum is for questions about MATLAB, not to help understand math and engineering concepts.

[XUAN LIU]

i am afraid what you said is not correct

Answer 3

[Marcos Fernandez]

Hi Akhil,

your suggestion is correct, try to multiply the signal by sin and cos.

Hope this helps.

Regards, Marcos