Interference Mitigation Against FMCW Signals Applicable Into IEEE 802.11ad for Intra-Vehicle Communications

It is expected that IEEE 802.11ad is used as intra-vehicle communications for high-speed transmission. Currently, since motion detection by frequency modulated continuous wave (FMCW) signals in mmW has been available, issues on interference between IEEE 802.11ad and FMCW signals have been raised. To solve the issues, an interference mitigation method applicable into IEEE 802.11ad against FMCW signals has been proposed. In this method, FMCW signals are detected by summation of the energy in frequency domain of interfered received signals. Interference suppression is achieved by nulling the frequencies where it is determined that FMCW signals are detected. The method does not require any changes of IEEE 802.11ad specifications. Simulation results show that significant improvement on BER has been achieved by introducing the method over SIR range from 0 dB to 8 dB. Experiment on the method has been conducted to evaluate performance of the method in a vehicle. The results obtained by the experiment have shown that the method successfully suppresses FMCW signals.