EMC’04/Sendai Suppression of Microwave Oven Interference in WLAN Systems Using Adaptive Filters

Since WLAN (Wireless LAN: IEEE802. 11b) systems shares the 2.4 GHz frequency band with microwave ovens, interference caused by the radiated noise from the ovens is a serious problem. This paper proposes the use of adaptive filters to suppress the microwave oven interference in DS-SS (Direct Sequence Spread Spectrum) WLAN links. This method is based on the fact that an oven noise can be regarded as a CW-like interference in a short duration. In contrast to the conventional suppression techniques for oven noises, this method can be implemented without any changes of the specifications of currently used WLAN systems. The results of numerical simulations clearly demonstrate the effectiveness of the method for improving the bit error rate of the WLAN links interfered by oven noises.