Some good USRP projects on 802.11

Implementation of Full-Bandwidth 802.11b Receiver

http://span.ece.utah.edu/pmwiki/pmwiki.php?n=Main.80211bReceiver

PHY-based Location Distinction
http://span.ece.utah.edu/pmwiki/pmwiki.php?n=Main.PHY-basedDistinction