- #1
Weightofananvil
- 34
- 1
Hey,
I'm learning about DSB and SSB in my communications classes and I'm a little confused with the concept.
So, We know that in a AM signal there is the Modulating signal (Information) and the Carrier signal (Transmission signal.) We also knows LSB and USB are created when the signals are combined
in DSB signals it is said that the carrier is suppressed and only 1 side band remains (SSB) It also says that at the "min" peak in the cycles there is a phase shift.
This confuses me a little bit because in my textbook they are only speaking of the transmission section of the am signals. Why would you want to eliminate the carrier if the signal hasn't been sent? It also says one of the main fall backs of SSB and DSB is that on the receiving end it is hard to remove the carrier signal. This all seems counter-intuitive of each other...
How I picture AM in my head is that the envelope of the carrier frequency is reshaped by the modulating signal. Due to my backround in audio I tend to think of the differences in sidebands, harmonics or anything of that nature in terms of the sound frequency spectrum and then just realize where it actually is on the spectrum. I understand that if the signal is single, you only need 1 side band which saves power but I don't understand what exactly is happening with the carrier.
Typically in textbooks they always show things with sin waves, but if USB and LSB are different frequencies then how is the modulated signal shown with just a single frequency? (aside from showing the signals before they are joined)
Hopefully these aren't all super silly,
but I've been waiting for it to click together.
Thanks in advance!
I'm learning about DSB and SSB in my communications classes and I'm a little confused with the concept.
So, We know that in a AM signal there is the Modulating signal (Information) and the Carrier signal (Transmission signal.) We also knows LSB and USB are created when the signals are combined
in DSB signals it is said that the carrier is suppressed and only 1 side band remains (SSB) It also says that at the "min" peak in the cycles there is a phase shift.
This confuses me a little bit because in my textbook they are only speaking of the transmission section of the am signals. Why would you want to eliminate the carrier if the signal hasn't been sent? It also says one of the main fall backs of SSB and DSB is that on the receiving end it is hard to remove the carrier signal. This all seems counter-intuitive of each other...
How I picture AM in my head is that the envelope of the carrier frequency is reshaped by the modulating signal. Due to my backround in audio I tend to think of the differences in sidebands, harmonics or anything of that nature in terms of the sound frequency spectrum and then just realize where it actually is on the spectrum. I understand that if the signal is single, you only need 1 side band which saves power but I don't understand what exactly is happening with the carrier.
Typically in textbooks they always show things with sin waves, but if USB and LSB are different frequencies then how is the modulated signal shown with just a single frequency? (aside from showing the signals before they are joined)
Hopefully these aren't all super silly,
but I've been waiting for it to click together.
Thanks in advance!