lomaxe
Member level 1
Hi everybody.
Before to ask my question I want to quote from the book named "Computer networks" by Tanenbaum A.
Given a bit rate of b bits/sec, the time required to send the 8 bits in our example
1 bit at a time is 8/b sec, so the frequency of the first harmonic of this signal
is b/8 Hz. An ordinary telephone line, often called a voice-grade line, has an
artificially introduced cutoff frequency just above 3000 Hz. The presence of this
restriction means that the number of the highest harmonic passed through is
roughly 3000/(b/8), or 24,000/b (the cutoff is not sharp).
The question is: why the author decided that the first harmonic of the signall is b/8 Hz? What is his logic? I don't understand.:lol:
Before to ask my question I want to quote from the book named "Computer networks" by Tanenbaum A.
Given a bit rate of b bits/sec, the time required to send the 8 bits in our example
1 bit at a time is 8/b sec, so the frequency of the first harmonic of this signal
is b/8 Hz. An ordinary telephone line, often called a voice-grade line, has an
artificially introduced cutoff frequency just above 3000 Hz. The presence of this
restriction means that the number of the highest harmonic passed through is
roughly 3000/(b/8), or 24,000/b (the cutoff is not sharp).
The question is: why the author decided that the first harmonic of the signall is b/8 Hz? What is his logic? I don't understand.:lol:
