Attitude High-dynamic Interference Suppression For GNSS Based On Array Antenna

The application of Global Navigation Satellite System is widely in the civil and military fields. GNSS is vulnerable to all kinds of interferences so that the anti-interference problem becomes the focus in the world. With the development of science and technology, more and more modern and advanced new weapons, such as missiles, may do high-speed revolution to be attitude high-dynamic state. Therefore, the DOAs of satellite signals and interference signals will change fast because of the carrier's instability, leading to the invalidation of conventional beamforming algorithms. Thus the search for attitude high-dynamic interference suppression for GNSS is necessary. Therefore, the attitude high-dynamic interference suppression algorithms for GNSS based on adaptive array antenna is discussed.Firstly, the mathematical models based on uniform line array and uniform circle array are built respectively, and the DOAs changes of the satellite signals and interference signals result from the attitude high dynamic are discussed. Under the uniform linear array, DOAs of signal and the interference change with the speed of the vehicle. Under the uniform circular array,the azimuth of the satellite signal changes quickly, but that of elevation is approximated to zero, which can be neglected. At the same time, azimuth and elevation of interference change quickly, and the elevation change of interference has a certain relationship with the carrier's speed and the distance between the carrier and receiver.Secondly, aiming at the uniform linear array, an algorithm of widening null and main lobe simultaneously interference suppression based on the known DOAs is proposed. The method can effectively track DOAs fast changes of interferences and signals, and can form gain in the direction of satellite signal to improve the signal to noise ratio. While it needs the knowledge of array manifold.Thirdly, an algorithm of widening null and main lobe simultaneously based on spread re-spread is proposed, which needn't know the array manifold and has a good robustness.Fourthly, aiming at uniform circular array, a null widening interference suppression method based on Capon is proposed. The method can effectively restrain the interference of rapid DOA change. Meanwhile, when the number of array is small, the satellite signal will not be easily removed from the main lobe.