The Federal Aviation Administration (FAA) Wide Area Augmentation System (WAAS) Monitoring Team has investigated increases in Radio Frequency Interference (RFI) events observed since 2009. The Oklahoma City-based WAAS Monitoring Team initially observe

Direct sequence spread spectrum (DSSS) communication systems has been widely used in these years for its advantage of wide spectrum, low working Signal-to-Noise ratio (SNR), anti-interference, anti-multipath effect and capability of LPI and LPD.