|
|
 |
 |
 |
 |
 |
 |
|
|
|
From: Jay Miller (jnmiller, cryptofreak dot org) Date: 2001.03.09 - 15.26 MST
X-Mailer: Mutt 1.2.5i
Okay, so here's the bottom line on how PSK works. There's two kinds
(that we're concerned about, anyway):
- Binary phase-shift keying (BPSK)
A change in phase indicates a change in the digital signal. So:
1 2 3 4
| | | |
/\ /\| |/\ |/\ /\|
|\/ \/| \/| |\/
This would be read either as '0110' or '1001'. The reading of each bit
is dependent on the bit previous to it. If no change in phase happens,
the digital signal stays where it is (ie. keeps reading '1's or
whatever).
- Differential binary phase-shift keying (DBPSK)
A change in phase indicates a '0'. A '1' is indicated by no change in
phase. So:
1 2 3 4
| | | |
/\ /\| |/\ |/\ /\|
|\/ \/| \/| |\/
This would be read as '0010'.
--
Jay Miller
ICQ: 32123421 | YM: ladenedge | http://www.cryptofreak.org
PGP: 0xedc9bb8d | 41a6428c 46abd36b 6b259b68 8a28ca4c edc9bb8c
--
This is the mod-chal mailing list. To unsubscribe, email
majordomo, cryptofreak dot org with message body 'unsubscribe mod-chal'.
Or, for more information, visit http://www.cryptofreak.org/.
This archive was generated by hypermail 2b30 : 2001.09.26 - 14.03 MDT |
