Adaptive Joint Interference Cancellation and Space-Time Block Decoding for IEEE 802.11b WLAN Systems

Digital transmission in wireless local area networks (WLANs) according to the IEEE 802.11b standard suffers from fading, intersymbol interference (ISI), and co–channel interference (CCI). In this paper, receivers with joint interference cancellation and time–reversal space–time block decoding (JICSTD) are proposed for an enhanced version of the IEEE 802.11b WLAN standard with space–time coded transmission. In IEEE 802.11b, complementary code keying (CCK) with a maximum data rate of 11 Mbit/s is employed as modulation format. The proposed receivers perform JICSTD in a first stage and equalization in a second stage. Minimum mean–squared error (MMSE–) JICSTD presuming perfect channel knowledge for all users and a training based least–squares (LS–) JICSTD for asynchronous interference are investigated, respectively. For subsequent equalization block–based reduced–state sequence estimation (RSSE) tailored for CCK transmission is used.