2
\$\begingroup\$

What is exactly the difference between the Bandwidth and the carrier frequency ? And if we have two channels with the same bandwidth but with different carrier frequency will we have different speeds ? For example :

  • System A : Bandwidth = 1 Khz , Carrier frequency = 1 Ghz

  • System B : Bandwidth = 1 Khz , Carrier frequency = 1 Mhz

If we used 16-QAM in both systems will baudrate be the same ?

\$\endgroup\$
  • \$\begingroup\$ Do you understand the answer to this question: Why is channel capacity a factor of bandwidth instead of frequency? \$\endgroup\$ – The Photon Oct 30 '17 at 22:57
  • \$\begingroup\$ Actually I couldn't understand this part " A single frequency signal would be a continuous tone. It's amplitude would never change. It would just continue on repetitively forever. As such, it would not convey any information." \$\endgroup\$ – Ali Safaya Oct 30 '17 at 23:10
  • \$\begingroup\$ I mean why would it continue repetitively ? If so wouldn't we be able to transmit data over it changing phase like in PSK ? \$\endgroup\$ – Ali Safaya Oct 30 '17 at 23:13
  • \$\begingroup\$ What is the fourier transform of \$\sin(\omega t)\$? If you change the phase then you have \$\sin(\omega t + m(t))\$. If you take the F.T. of this, you won't get the same as for the simple sine, you'll get something spread over a band of frequencies. Put another way: once you modulate the phase, you no longer have a single-frequency signal. \$\endgroup\$ – The Photon Oct 30 '17 at 23:19
  • \$\begingroup\$ So the answer to the question is yes and speed stay the same ? \$\endgroup\$ – Ali Safaya Oct 30 '17 at 23:25

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.