Anti-jam Technique Research For GPS

As GPS receiver is used widely both in the civil and military affairs. The vulnerability of GPS and GNSS to that interference is becoming visible. The research on GPS jam and anti-jam field is just beginning in China. So it is very significant to design anti-jam RF circuit, to build anti-jam model and to build evaluation system for GPS anti-jam. The work in this paper is as below:This princeple of the GPS receiver and some interference characters analyse is introduced in this paper. Based on this, the total solution for GPS anti-jam is given in this paper. In the paper, we have designed the RF circuit and induce the technique of RF filter which can mitigate out of band interference. For another receiver with multiple antennas, We also give the Space-time adaptive signal processing algorithm and build the model of based on EKF.In the model, the narrowband jammers are modeled as vector autoregressive (VAR) processes and rejected by temporal whitening. The spatial nulling is implicitly achieved by estimating a sample covariance matrix and feeding its inverse into the extended Kalman filter (EKF). Computer simulations demonstrate robust performance of the algorithm in severe jamming. In addition, We build the experiments platform in order to Measured Effects of a Narrowband Interference Suppressor on GPS Receivers with a single antenna. The platform consists of E4438C vector signal generator,Advanced Design system,GPS receiver.The solution evaluate the performance of GPS receiver with/without Narrowband Interference Suppressor.The result shows the Narrow Interference Suppressor can mitigate narrow interference to GPS.