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In amplitude modulation, one of the single sideband techniques is to reduce the carrier power instead of supressing it altogether. Is there an advantage to doing this and having some of the carrier signal or power still be present, as compared to suppressing the carrier completely? I mean technically, more power is saved when it is completely supressed. Does it have anything to do with demodulation?

AndroidV11
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  • Can the same reasoning be applied to SSB-RC vs SSB-SC? Though I want a deeper explanation focusing on SSB for anyone who can pull it off. – AndroidV11 Apr 07 '21 at 08:01

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Does it have anything to do with demodulation?

Leaving a small bit of carrier energy is entirely to make demodulation a lot easier. If you can extract the carrier from the transmission you can synchronously demodulate the single sideband back to baseband relatively easily. It's also very similar to vestigial sideband modulation and here's a reference for Full, reduced, and suppressed-carrier SSB.

Andy aka
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  • What is the difference in demodulation when compared to the carrier being supressed? Is it impossible or harder? I want to know why reduced carrier is used more commonly than supressed carrier so I want to know the significance of that choice. – AndroidV11 Apr 07 '21 at 12:44
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I'm not 100% sure if it's the same as sideband suppression in I/Q but the issue is that full sideband suppression is somewhat critical. It is possible that it's simple easier (i.e. cheaper) to leave some of the sideband pass through.

Lorenzo Marcantonio
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    I was referring to supressing the carrier, not the sideband part though. But yeah, single sideband does mean the other sideband is supressed. – AndroidV11 Apr 07 '21 at 06:34