1. 1 Performance Enhancement for Wi-Fi Communications Presented by Tanim M. Taher

2. 2 Study of Interference by MicroWave Ovens (MWO) Why can I never connect to the internet during lunch time everyday?

3. 3 Experimental Analysis of MWO Signal The Residential MWO signal is synchronized with the 60 Hz AC line cycle, and it radiates in the positive half cycle only. The MWO signal has the main characteristics: 1.An AM-FM signal that is radiated for about 5-6 ms. 2.Transient signals before and after FM signal (~1ms). “On” cycle of MWO

4. 4 Power Spectral Density of MWO Signal Most power is concentrated over the narrow frequency range (15 MHz) swept by AM-FM signal. There is power scattered over entire ISM band. The wideband power is due to transients.

5. 5 MWO Signal Model “On” cycle of MWO

6. 6 MWO Signal Spectrogram

7. 7 Interference Spectrogram

8. 8 Interference Mitigated

9. 9 Experimental BER ResultsMWOCaseBER1 NO MITIGATION 11.29% 2 1.661% 3 0.7315% 1MITIGATION0 2MITIGATION0 3MITIGATION0

10. 10 Interference Mitigation Technique Data transmission using 802.11 channel 1 (shaded areas are transient locations)

11. 11 Thank you! Questions? Tanim Taher (tahetan@iit.edu)