Re: [SOCALWUG] Difference between Frequency and Phase?

[Sanford Weinberg]

Great question... you are correct in that frequency is how long it takes to 
complete one cycle (cycles per second) and phase is where it 
starts...Disclaimer: this explanation is simplified for the concepts - 
Remember this is a digital system.  we don't look at the entire wave just 
if we are at a peak or baseline at specific (sample) times.  If we have a 
frequency of one cycle per second (1 hertz) then to send one character 
would take us typically 8 - 10 seconds (bit by bit plus overhead bits). 
Remember my choice of frequency is probably limited by what I want to use 
it for and the FCC

If I synchronize clocks on receiver and sender and I can process faster 
then my frequency (say a tenth of a second in our example) then I can send 
out theoretically 10 signals on the same frequency of 1 cycle per second at 
different phases and get the character in one second instead of 8-10.

Let me know if you more detail is needed

At 02:58 AM 12/18/2003, you wrote:
Hello,

Im having difficulties understanding exactly what Phase means, Im reading 
802.11 Wi-Fi handbook
(Neil Reid&Ron Seide) which explains that frequency is the complete cycle 
of a wave.
Phase is where the wave begins its cycle. Makes sense I guess.
What becomes confusing is BFSK and BPSK, BFSK sends an on or off bit with 
each frequency,
BPSK sends two states, a "one" with one phase and "zero" with another phase.
If phase just determines at what point in time a frequency begins its 
cycle, how can there be a modulation scheme based on phase?

Thanks

--------------------
"Computer games don't affect kids, I mean if Pac Man affected us as kids, 
we'd all run around in a darkened room munching pills and listening to 
repetitive music." - Kristian Wilson, Nintendo, Inc, 1989.

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