Research On Pulse Interference Suppression For Global Navigation Satellite System

Global Navigation Satellite System (GNSS) was introduced by InternationalCivil Aviation Organization (ICAO), with the goal of integrating the satelliteconstellation (GPS, GLONASS, Galileo, and Compass), the augment systems, and theairborne navigation system (Inertial Navigation System, INS). And finally the GNSSwill turn to be a “system of systems”. Accomplishing the performance requirementsof accuracy, availability, continuity and integrity, GNSS plan can make it possible toposition the civil aircrafts accurately, enhance the flexible design of flight route,improve the traffic capacity, reduce the dependency of aircraft on ground-based radionavigation equipment, and cut down the maintenance cost of ground navigationequipment. Then finally the goal of global operation can be achieved.However, during the progress of building and developing, the GNSS is sufferingfrom the interference of various radio equipment. Especially, the GPS L5, CompassB2and Galileo E5signal are interfered severely by the Distance MeasurementEquipment (DME).This dissertation has carried out deep research on the problem of aeronauticalradio interference on GNSS, and the achievements are shown as follows:1. Considering the problem of gapped data caused by using the conventionalinterference method, we propose a DME pulse interference suppression method basedon modified GAPES. This method utilizes the data obtained after hybrid filtering asinitial values of the iteration progress, and then the gapped data are estimated andrestored. Due to taking advantage of full information of received signals, the gappeddata can be estimated and restored efficiently, at the same time the DME pulseinterferences are suppressed.2. Taking account of the DME interference from a single ground base, wepropose a DME interference approach based on NLS. This approach takes the DMEinterference as signal of interest (SOI). Firstly the frequency and amplitude of SOI areestimated, then DME signal is reconstructed, and finally the interference issuppressed.3. For multiple DME interferences from ground base, we propose an interferencesuppression method based on RELAX. This method makes use of the RELAXalgorithm to iterate and then estimate frequency and amplitude of every interference,and then reconstructs the interferences separately. Finally the interferences aresuppressed.4. Due to the characteristic of generalized cross correlation between the twosignals received by the antenna of airborne DME antenna and the one received byGPS antenna, we propose an interference suppression method based on adaptivecancellation. This method firstly estimates the time delay between two antennas, andthen compensates the time delay and attenuation between the two signals. Finally thegoal of DME interference suppression is achieved by adaptive cancellation.