Diversity techniques for interference mitigation between IEEE 802.11 WLANs and Bluetooth

Wireless LANs (for e.g., IEEE 802.11g) and wireless personal access networks (WPANs) operate in the same 2.4 GHz ISM frequency band. In this paper, we consider the techniques to mitigate the interference caused by WPANs (e.g., Bluetooth) on the IEEE 802.11 wireless LAN. In particular, we consider the downlink where an adjacent Bluetooth device interferes with a WLAN station. We show that a simple frequency diversity scheme makes the IEEE 802.11 WLAN robust to the narrow band interference caused by a Bluetooth device. We also propose an interference cancellation algorithm which estimates the interference and reconstructs the WLAN signal (which is interference free). We compare our scheme with that of the existing architecture. We show that our scheme offers a significant gain compared to the existing architecture. Other techniques like error control coding may also be used for interference mitigation. But, coding does not exploit the inherent frequency diversity gain that we show in this paper. Hence, the performance of our scheme would be much better than what one would expect with coding techniques