Rejection of Bluetooth interference in 802.11 WLANs

We investigate the use of complex coefficient adaptive filters for interference suppression in the direct sequence spread spectrum IEEE 802.11b system. Extensive simulations are carried out to optimize the parameters of a recursive least-squares lattice filter, which mitigates the effect of a hopping narrowband interferer such as Bluetooth. The BER curves, as well as the probability of packet loss, are presented. Moreover, the limitations of the adaptive filter approach, in the suppression of multiple jammers, is determined. It is shown that with a low order filter, the hopping jammer can be successfully suppressed.