Semi-Blind Channel Estimation on 802.11 OFDM Data Symbols

New wireless local area network designs are placing a greater emphasis on reliability, which motivates a re-examination of physical layer protocols. It also motivates techniques to improve the reliability of legacy protocols, since legacy protocols are often used alongside new protocols. This paper introduces a technique for receiving legacy IEEE 802.11 packets when the PHY header is corrupted or unavailable by performing a blind or semi-blind channel estimation using unknown data symbols. The technique can improve reliability by allowing reception of packets that would otherwise be discarded. It also suggests additional features that could be added to future wireless local area network standards to improve reliability.