At 10:32 PM 1/28/06, you wrote: >Respectfully, you are talking about compressing the content. That won't help >with cramming a 5600 baud circuit into a 2400hz bandwidth. It might help send >more content faster - making a slower circuit "look" like a 5600 baud >circuit, but it won't help put a 5600 baud circuit into a 2400hz bandwidth. > >Anybody else got any ideas? > >tim ab0wr
One encounters a fundamental problem with Nyquist in attempting to use a signaling rate that's more than twice the baseband bandwidth. If the baseband signal is then translated to RF with a balanced modulator, the occupied bandwidth doubles. In this case a signaling rate equal to the occupied RF bandwidth, i.e. 2400 baud for a 2400 Hz bandwidth, is the limit. That said, it's readily possible to fit a 5600 bit per second data stream into a 2400 Hz bandwidth by picking a modulation scheme that has a bandwidth efficiency of greater than 2.33 bits/s per Hz; in this case, 8-PSK at a signaling rate of 1867 baud is but one way to send 5600 bits per second over a 2400 Hz BW channel. 73, Mike K1MK Michael Keane K1MK [EMAIL PROTECTED] Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
