luckyvictor
Member level 4
Can someone please explain the following statement? why is twice please?
"PAM signals occupy twice the bandwidth required for the baseband."
And let say I have a PAM signal, the time waveform is at frequency 5kHz, then what is its bandwidth please?
Now the second statement is,
"When having bandwidth W for the QAM and the PAM modulaton schemes we have symobl rates 1/T, then 1/T = 2W for PAM and 1/T = W for QAM"
why is this the case?
And let say I have a QAM signal, the time waveform is at frequency 5kHz, then what is its bandwidth please?
Lastly, given the above statement we have,
"modulation efficiency R/W = 2b for PAM and R/W = b for QAM, where R is data rate and b is number of bit"
therefore according the above statement, for a given W and b, PAM is transmitting double the data rate R, why? are we not expecting QAM to transmit double since it uses two waveforms at a time.
thank you so much
"PAM signals occupy twice the bandwidth required for the baseband."
And let say I have a PAM signal, the time waveform is at frequency 5kHz, then what is its bandwidth please?
Now the second statement is,
"When having bandwidth W for the QAM and the PAM modulaton schemes we have symobl rates 1/T, then 1/T = 2W for PAM and 1/T = W for QAM"
why is this the case?
And let say I have a QAM signal, the time waveform is at frequency 5kHz, then what is its bandwidth please?
Lastly, given the above statement we have,
"modulation efficiency R/W = 2b for PAM and R/W = b for QAM, where R is data rate and b is number of bit"
therefore according the above statement, for a given W and b, PAM is transmitting double the data rate R, why? are we not expecting QAM to transmit double since it uses two waveforms at a time.
thank you so much