1. Preliminary Coexistence Tests The same 802.11 wireless signal was used as the victim: – Power Level = 0 dBm – BW = 20 MHz – Center Frequency = 2.412 GHz – Orthogonal frequency-division multiplexing (OFDM) Data Rate = 6 Mbps – BPSK

2. OFDM concept Transmit data is spread over a number of orthogonal subcarriers in the frequency domain

3. Error vector magnitude (EVM) measurement of the receive signal constellation

4. Comparing Impacts of Different Interference Modulation/Technologies Setup – Currently conductive – Eventually move to radiated Target protocol – WLAN Interfering Modulation/Technologies – CW AM Signal – Bluetooth (BT) – LTE – WLAN

5. Peak Spectrum of 802.11 WLAN Test Signal

6. Recieved WLAN Constellation, no interference.

7. Recieved WLAN EVM Spectrum with no Interfering signal

8. Interfering signal spectrums (with 20 MHz WLAN at center frequency = 2.417 GHz)

9. Interfering Signal 1: CW AM Signal Parameters: – Center Frequency = 2.41 GHz (within, but off center, of WLAN band) – AM Modulation: 1 kHz and 80% (as in IEC 61000- 4-3, Annex A) – Power level = -10 dBm WLAN does not fail RMS EVM of approx. -23 dBm (by inspection) as an instant average over all subcarriers

10. Recieved WLAN Constellation from Interfering Signal 1

11. Recieved WLAN EVM spectrum from Interfering Signal 1

12. Interfering Signal 2: Bluetooth Parameters – Power Level = -10 dBm – Center Frequency = 2.41 GHz (same as Signal 1) – Max Payload length, Carrier Burst WLAN intermittently fails as a result of the BT signal RMS EVM of WLAN is regularly about -50 dBm (by inspection), with short periods of Higher EVM (at failure) – Consistently much lower EVM from signal 1

13. Received WLAN Constellation with Interfering Signal 2, WLAN Failure

14. Recieved WLAN EVM Spectrum with Interfering Signal 2, WLAN Failure

15. Interfering Signal 3: LTE Parameters – Power Level = -10 dBm – Center Frequency = 2.41 GHz – BW = 10 MHz With these Parameters the WLAN Receiver was never able to establish a link

16. Interfering Signal 3: LTE Cont. Highest 10 MHz LTE power that allowed the WLAN system to make a connection was -27 dBm – Consistent EVM of about -25 dBm (by inspection) – Large number of subcarriers are affected (see following EVM plot) by this signal – This is due to the wider bandwidth of LTE compared to Bluetooth or the CW AM signal

17. Received WLAN Constellation with Interfering Signal 3 (-27 dBm Power)

18. Recieved WLAN EVM Spectrum with Interfering Signal 3 (-27 dBm Power)

19. Interfering Signal 4: 802.11 WLAN The interfering WLAN is on the 802.11 band nearest the victim: – Power = -30 dBm – Center Frequency = 2.417 GHz – BW = 20 MHz -30 dBm interference power setting was the highest that allowed consistent victim connection Consistent average RMS EVM of about –29 dBm (from inspection)

20. Recieved WLAN Constellation from Interfering Signal 4

21. Recieved WLAN EVM spectrum from Interfering Signal 4

22. Backup Slides

23. Received WLAN Constellation with Interfering Signal 2, No WLAN Failure

24. Recieved WLAN EVM Spectrum with Interfering Signal 2, no WLAN Failure

25. Peak Spectrum Comparison of CW AM, Bluetooth, and LTE from Tests