| Since the electromagnetic environment becomes more and more complicated and interference techniques continously develop, the application of satellite navigation systems is faced with many grave challenges. The interference suppression techniques already formed as one of the foundations of the successful application of satellite navigation system, it has been widely applauded by the general public and attracting great research attention because it is directly related to navigation warfare. According to the characteristics between the desired signal and interference signal in different dimensions such as time dimension, frequency dimension and spatial dimension,multidimensional interference suppression techniques can be effectively raise anti-jamming capability of the satellite navigation system by suppressing interference in differenct dimensions. Against this background, in this work we focus on the multidimensional interference suppression based on the needs of interference suppression in the case of multiple interference coexistence and the low complexity of interference suppression algorithm. The main contributions and innovations of the dissertation are summarized as follows:1. We propose an innovative double overlapping subarrays architecture for three-stage spatial processing for incoherent interference and multipath suppression in global navigation satellite system. The proposed algorithm combines pre-correlation, post-correlation beamforming techniques and spatial smoothing technique with double overlapping subarrays architecture for three-stage spatial processing. First, incoherent interference is suppressed by applying pre-correlation beamforming with subarray architecture; Then, the coherent signal identification, including source number detection and direction estimation of coherent signals, is used to suppress multipath components based on spatial smoothing scheme for decorrelation of post-correlation subarray signal vector; Finally, an effective beamforming algorithm is proposed for incoherent interference and multipath suppression by using the accurate direction-of-arrival estimation of the line-of-sight signal, multipath components and incoherent interference to solve the constraint optimization problem. Computer simulations are presented to demonstrate the validity and robustness of the proposed algorithm. Results show that the proposed algorithm can estimate the direction-of-arrival of the line-of-sight signal accurately at low SNR condition as SNR ≤-40 dB, meanwhile put deep nulls in the direction of the incoherent interference and multipath, and has better performance in high SNR compared with pre-correlation beamformer.2. We propose a novel time-domain adaptive filtering algorithm based on non-continuous interval filter in order to solve the problem of spread spectrum signal distortion caused by raised correlation between the samples, when general time-domain adaptive filtering narrowband interference suppression method is used in the oversampling direct sequence spread spectrum system.The proposed algorithm avoids the correlation between the samples of filter input and the performance deterioration of navigation signal caused by traditional time-domain adaptive filtering algorithm on the basis of non-continuous interval filter structure. Both theoretical analysis and simulations illustrate that, the proposed algorithm can not only put nulls in the interference frequency, but also has a much fltter amplitude-frequency characteristic than the traditional adaptive filters. Meanwhile it can suppress the interference effectively at both high and low signal-noise-ratio.3. To explore the effect of interference suppression on measurement zero value for satellite navigation receiver, we discuss from two aspects: carrier phase measurement zero value and pseudorandom code zero value. We present the model of receiver tracking loop with interference suppression, establish the equivalent filter model for classic interference suppression algorithm, and the expression of carrier phase measurement zero value bias and pseudorandom code zero value bias are derived. Then the conditions for the unbiasedness of carrier phase measurement zero value and pseudorandom code zero value are obtained. Both theoretical analysis and simulations illustrate that, there is no deviation of measurement zero value when the equivalent filter of interference suppression has the linear phase characteristic; carrier phase measurement zero value bias which is caused by the non-linear phased equivalent filter, can be compensated through formula(5.27); code phase measurement zero value bias which is caused by the non-linear phased equivalent filter, can be determined from the correlation function of the filter and pseudo code correlation function. The simulation results validate the correctness and effectiveness of the proposed analytical model. It can be used to guide the design of the interference suppression algorithm in satellite navigation receiver, and the performance of the range measurement is ensured by the interference suppression.4. In order to meet the project requirements of developing the XX-1 interference detection and suppression in satellite navigation receiver and XX-1 interference detection and suppression in crosslink, a design sheme and implementation result of interference suppression model is proposed based on the hardware designment of anti-jamming receiver, low complexity interference suppression algorithm and Field-Programmable Gate Array implementation. In order to verify the performance of the anti-jamming module, we present the test platform and specific test items of intermediate frequency testing, radio wireless-testing, radio wire-testing, temperature testing and switch testing. Finally the test results on the verification platform are shown. The test results show that the interference suppression model can meet the project requirements and the undertaken projects have been successfully delivered.
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