Research On TDOA/FDOA Estimation Of Interference Localization For Satellites

The process of satellite interference localization has two steps: first, estimate the corresponding parameters; then, using some algorithms and the estimated parameters to compute the location of the interference. The key of the technology of satellite interference localization is the measurement of the parameters. The crucial technique of system of double-satellites localization lies in the estimation of TDOA and FDOA with high precision. At present, the joint estimation methods of time delay and frequency shift for satellite interference localization are mainly based on the principle of correlation, such as CAF algorithm. CAF algorithm adopts two-dimension peak search, so it's time-consuming and its computation burden is heavy, which hardly reaches the speediness and nicety requirements.In this thesis, it mainly studies the estimation of TDOA and FDOA under Gaussian noise circumstance, as well as the joint estimation of TDOA and FDOA. First, because the traditional algorithm of TDOA estimation cannot restrain the influence of the correlated noises, an algorithm based on fourth-order cumulant is brought. Second, for the shortage of only using FDOA, the estimating algorithm based on fourth-order cumulant of FDOA is brought forward. At last, it deeply studies the joint-estimation of TDOA and FDOA, then brings two algorithms SD-SOS and SD-HOS, which transforms CAF based on two-dimension search into two one-dimension parameter estimation. The two algorithms both greatly reduce the computation burden. SD-HOS can estimate the location parameters effectively under various Gaussian noises circumstance, but SD-SOS is only applied in the circumstance of uncorrelated noises. In the thesis, all the algorithms developed have been proved and simulated in detail, whose results have certain theoretic significance and values in practice.Finally, a conclusion of the thesis is presented, and some further prospects of the research are made.