Hi:
Which phone-line* modem uses only MPSK [Multiple-Phase-Shift-Keying] as the modulation scheme *and* which uses the most phases -- i.e. most bits-per-symbol? What is the carrier frequency of the MPSK signals when there is no modulation signal?
Binary PSK uses the least amount of bits-per-symbol -- only one -- this means only two phases are used.
I am curious as to which phone-line* MPSK modem uses the most bits-per- symbol. Also, is this modem compatible with Windows 3.0? With DOS?
*Phone-line modem telecommunicates with the rest of the world by dialing numbers on phone lines -- similar to a dial-up modem or TTY device.In addition, my other questions are:
- What is the maximum amount of bit-per-symbol of MPSK that can be broadcasted via phone-lines?
- If I were to demodulate the MPSK carrier signals used by the above MPSK modem and then convert them to analog, and then pass these signals through a loudspeaker, what would I hear?
I tend to be interested in weird things -- particularly with sounds and telecommunications interferences, as well as as certain error messages. I don't know why.
As for question 2, regarding the MPSK sounds, it would probably sounds like a fax machine, if I hear it directly. However, if the MPSK is demodulated [using a device that demodulated phase-modulation signals at the carrier frequency used by this MPSK], and then converted to analog [actually passing through a DAC], I believe I would hear something *very* different -- I would hear the modulation signal instead of the carrier signal.
It's like listening to radio. You are supposed to be hearing the modulation signal, not the carrier signal -- and that too, the if the modulation signal is initially digital, it will have to be converted to analog in order to be perceived as sound.
But then, maybe I'm getting a bit confused.
In this case, it seems like the MPSK signal is the carrier wave. So in order to hear the modulation-wave [what I would like to hear], the MPSK signal would have to be "phase-demodulated". Since this modulation signal is digital [from demodulating the MPSK, which is also digital], this modulation signal would have to be passed through a DAC, in order to get the intended analog audio signal.
BTW, lets say there are a 1,000 phone lines with different numbers. OPSK [8-bits-per-symbol] signals with a baud of 1-symbol-per-second is broadcasted on each line. Is it possible get a speed of 8,000 bits-per- second, by using all the lines?
Each line carries 8-bits-per-symbol and 1-symbol-per-second, hence 8- bits-per-second. Is it possible to increase the speed to 8-kilobits- per-second by using 1,000 lines?
If so, then collectively, the baud would be 1,000 symbols per second because each line is convey 1 symbol per second.
Thanks