Interference Suppression Methods For Satellite Navigation System And Its DSP Design Based On QR Decomposition

GPS navigation systems are all around all areas of our lives constantly, but becausethe power of the GPS satellite signal arriving to the Earth’s surface is very low, at thesame time, some of its emission frequency and modulation characteristics are known,the GPS receiving system can be interfered intentionally or inadvertently, interferencesuppression will become one of the absolutely necessarily ability for GPS navigationsystems. Usually, the power of the navigation interfere is much higher than the GPSsatellite signal, so the condition number of the covariance matrix which is calculated bythe traditional matrix inversion and adaptive anti-jamming methods is very large, andthis will lead to the output capability of the anti-jamming descended or even invalidated.To this issue, an interference suppression methods for satellite navigation system and itsDSP design based on QR decomposition is investigated, so as to improve the conditionnumber and the numerical stability. Firstly, some math methods of QR decompositionare introduced; Secondly, QR decomposition SMI interference suppression methodsbased on the mean square domain and the data square domain are given, QRdecomposition subspace projection interference suppression method is put forward. Thismethod does not need to know the interferer number and the direction where the wavecomes, and the effect interference suppression is stabilized. Finally, the QRdecomposition subspace projection interference suppression method is applicated on theADSP-TS101S chip, the result of the measure data processing prove that the capabilityof the interference suppression is good, and the multi-satellite capture is achievedsuccessfully.