Spectrum Inversion

Hi,
I have recorded a signal that is spectrum inverted. I’ve heard that it’s
possible to restore the signal by “swapping” I and Q, but I remember
that there was a “minus” to intruduce in-between.
Could you please help me, giving me the exact transformation to apply,
and eventually the associated limitations.

Thank you,

Pepito

Pepito31 Pepito31 wrote:

Hi,
I have recorded a signal that is spectrum inverted. I’ve heard that it’s
possible to restore the signal by “swapping” I and Q, but I remember
that there was a “minus” to intruduce in-between.
Could you please help me, giving me the exact transformation to apply,
and eventually the associated limitations.

You can invert the spectrum of a complex signal by doing ONE and ONLY
ONE of the following:
swapping I and Q
negating I
negating Q

Matt

Matt E. wrote:

Pepito31 Pepito31 wrote:

Hi,
I have recorded a signal that is spectrum inverted. I’ve heard that it’s
possible to restore the signal by “swapping” I and Q, but I remember
that there was a “minus” to intruduce in-between.
Could you please help me, giving me the exact transformation to apply,
and eventually the associated limitations.

You can invert the spectrum of a complex signal by doing ONE and ONLY
ONE of the following:
swapping I and Q
negating I
negating Q

Matt

Thanks Matt,
For information, is this transformation only valid for a transformation
for a carrier centered on 0, or is it applicable to a carrier located
everywhere on the spectrum ?

Pepito

Pepito31 Pepito31 wrote:

Thanks Matt,
For information, is this transformation only valid for a transformation
for a carrier centered on 0, or is it applicable to a carrier located
everywhere on the spectrum ?

Pepito

It will reverse the entire signal.

Matt