> Please don't treat the radio part of these systems as a simple black > box that replaces an ethernet wire! Please do the homework required > to understand what happens in your radio at RF both on transmit and > receive. In other words, do a little RF engineering in addition to > the baseband and digital processing engineering. > Jim WA0LYK
There is, of course, no "magic" involved. If I may I will again attempt a layman's perspective. Chaos Theory may work to our advantage here. There is often much order embedded in what appears to be chaos. What *appears* to be an impossibly high signal-to-noise-ratio to an analog system is often overcome by a sharp ear and/or DSP processing. "Noise" as we generically label it appears to be impossible QRM/QRN chaos unless broken down into component parts. If we have good propagation such that a strong signal *may* be received from the desired source and some irresponsible vendor injects BPL QRM/QRN into the spectrum then we have a known source which may be excluded via RF signal and digital processing. We have nulling technologies to remove some of the RF signal and digital to exclude non-relevant QRM/QRN. If we have poor propagation such that the desired signal would already have trouble getting to our receiver then the added BPL QRM will make a difficult problem more so, perhaps but not necessarily impossible. If our transmission is in known packets and BPL QRM/QRN successfully attacks a packet it is resent until completed. As you noted, if we boost the power level of the transmission we enhance the probability of overcoming the BPL QRM/QRN, but we do so at the price of increased cost and added energy -- which may be a precious commodity in an emergency deployment. We also risk generating our own QRM/QRN to nearby Ham & non-Ham gear. What am I missing? -- Thanks! & 73, doc, KD4E ... somewhere in FL URL: bibleseven (dot) com 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/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> 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/
