Performance analysis of interference problems involving DS-SS WLAN systems and microwave ovens

Theoretical and experimental investigations are carried out on the degradation in the performance of DS-SS wireless LAN systems (WLANs) (IEEE802.11b) systems caused by electromagnetic noise radiating from microwave ovens in the 2.4-GHz frequency band. Based on the time-domain oven-noise model, theoretical expressions for short-duration bit-error rates (BERs) and packet-error rate (PERs) are derived. Measurements were done using commercially available microwave ovens and a noise simulator that consisted of a function generator and an RF synthesizer. The PERs measured with actual oven noise were found to correlate well with those derived by simulated noise, and they were in reasonable agreement with the theoretical estimates given by the derived approximate formulae. It is concluded that the noise simulator and the derived approximate expressions were very useful in evaluating the BER and PER of WLAN systems that have incurred interference from microwave ovens.