Can analog communication systems overcome errors in transmission better digital CS?
this site says it cannot overcome it better <http://cnx.org/content/m0074/latest/%3E whereas this one says the other <http://en.wikibooks.org/wiki/Communication_Systems...
I am confused
- J. FrostLv 68 years agoFavorite Answer
You cannot 'really' correct errors in an analogue system. In an analogue system the signal can take on any arbitrary value: there is no way you cant tell the difference between noise and the real signal (that is, noise which is in band with the signal). We can correct errors in digital transmission because we only allow the signal to take on some finite number of values. If we recieve something 'in between' these values we know it was an error.
In reality all commonications are analogue because the physical signal is analogue. what we are talking about is the encoding of information. In reality we can successfully send usable information over a digital channel with a much lower signal to noise ratio than an analogue channel: a simple example: say we had a telephone line, one analogue and one digital which uses regular pcm to encode samples, and transmitts them as a baseband NRZ line signal. Then the digital line could work perfectly with a signal to noise ratio of 6db, noise voltage half the signal voltage, because then a simple quantiser would correctly decode the correct level all the time, and the recieved quantised signal would be perfectly noise free: a 6db SNR with an analogue telephone line would be unusable for ordinary conversation!
- youngmanLv 45 years ago
Good the analog clocks are ordinarily louder but very likely to loud it could startle you wen u rise up and the digital are less complex to install but pushing the discontinue button even as your half asleep can be challenging