Re: Single Side Band (SSB) Demodulation

Tim Wescott <tim@xxxxxxxxxxxxxxxx> writes:

Howard Long wrote:
Hi Bangash

Actually I am working on Single Side Band (SSB)
Modulation/Demodulation. I have successfull programmed the Modulator and
the Demodulator. But Now I have one problem, that I want extract the
Carrier Frequency from the SSB (transmitted) signal at the receiver end.
Any one can guide my in the respect.
In practice, SSB is almost always suppressed carrier, so there is no
carrier transmitted. Unlike tuning an AM or FM receiver where the
precise frequency is not required, for SSB-SC the receiver needs to
be manually adjusted to the right frequency by the user so that it
sounds right.
Perhaps I haven't understood your problem properly.
HTH, Howard
In theory, if it's voice over SSB that's being transmitted, you can
automatically fine tune the SSB receiver. This works (purportedly)
because the vocal cords generate a comb of frequencies, which the
vocal tract shapes. So you can do an FFT, then extract the virtual
zero point of the comb, then servo to it.

There was an article in QEX on this technique years ago. I suspect
that it doesn't really work all that well, because I don't see any
amateur radio receivers being sold with automatic fine tuning on SSB.

Assuming cos[(omega+delta)*t] is your LO, then couldn't you try simply adapting
the tuning until the energy in sin[(omega+delta)*t]*x(t) is minimum (ideally,
zero)? This is from the idea that, if the tuning is correct, there will be
no imaginary component in a quadrature downconversion.

This is from the hip, so I could be out in left field.
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Relevant Pages

  • Re: Comm. Circuits - SSB Question
    ... > SSB receiver to compensate for the lack of a full carrier in SSB ... If you want exact, you start with a crystal controlled transmitter, ...
    (sci.electronics.misc)
  • Re: Single Side Band (SSB) Demodulation
    ... In practice, SSB is almost always suppressed carrier, so there is no carrier transmitted. ... Unlike tuning an AM or FM receiver where the precise frequency is not required, for SSB-SC the receiver needs to be manually adjusted to the right frequency by the user so that it sounds right. ... So you can do an FFT, then extract the virtual zero point of the comb, then servo to it. ...
    (comp.dsp)
  • Re: Single Side Band (SSB) Demodulation
    ... But Now I have one problem, that I want extract the ... Carrier Frequency from the SSB signal at the receiver end. ...
    (comp.dsp)
  • Re: Single Side Band (SSB) Demodulation
    ... Modulation/Demodulation. ... In practice, SSB is almost always suppressed carrier, so there is no carrier transmitted. ... Unlike tuning an AM or FM receiver where the precise frequency is not required, for SSB-SC the receiver needs to be manually adjusted to the right frequency by the user so that it sounds right. ...
    (comp.dsp)
  • Re: Single Side Band (SSB) Demodulation
    ... Modulation/Demodulation. ... Carrier Frequency from the SSB signal at the receiver end. ...
    (comp.dsp)
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