Researches On Antenna Mutual Coupling Calibration And Anti-Jamming Algorithms In Navigation Receiver

Satellite navigation technology is the world’s one of the three informationtechnology industries, and plays a crucial role in the national economy and the people’slivelihood.However, due to the navigation satellite from Earth remote and the spreadspectrum modulation characteristics of the navigation signal itself, resulting in thereceiver the power of the received navigation signal is very weak and vulnerable to awide variety of interference, so researches on anti-jamming technology in navigationreceiver have a very important significance.Navigation anti-jamming technology basedon space-time adaptive beamforming processing can effectively inhibit multiplemalicious broadband and narrowband interferences by increasing the antenna backenddelay units.The article first research on power inversion algorithm which is most commonlyused in STAP anti-jamming technology.Since the structure of the optimal solution of thepower inversion algorithm and the MVDR algorithm are very approximate,we simulateand compare the anti-interference performance of this two algorithms.In addition, thearticle also research on the structure of the optimal solution of power inversionalgorithm from the perspective of the eigenvalue decomposition.We theoreticallyanalyze the cause of the poor ability to suppress weak interference of power inversionalgorithm and put forward an improved algorithm.Taking into account the mutual coupling can affect the anti-jamming performanceof STAP technology, the article immediately research two antenna mutual couplingcorrection compensation algorithms,separated iterative algorithm and the loss rankalgorithm. Both algorithms use the inverse matrix of the estimated value of the mutualcoupling matrix to compensate system. Simulation results show that the loss rankalgorithm can not only efficiently compensate the system performances losses but alsohave more concise calculation and better performances than separated iterativealgorithm under circumstance of higher input interferer to noise power ratio.So the lossrank algorithm is more suitable for practical engineering applications.In traditional dimensionality reduction processing based multistage wiener filter algorithms, mean square error with dimensionality reduction series converges isdifferent under different interference circumstances.This often leads to using a fixedthreshold difficult to cope with the actual varying interference background.Therefore wepropose a new diagonal loading method to reduce the performance loss ofdimensionality reduction stages over-estimated. Simulation results show that thismethod is effective and when diagonal loading approximately equal to the noisepower δ_N~2N, the improved effect is the best.Finally, the paper research on subspace orthogonal projection algorithms in STAPanti-jamming technology. First, simulations and comparisons of the anti-jammingperformance of the eigenvalue decomposition algorithm and the MWFD subspacealgorithm based on the multistage wiener filter forward recursion process areprovided.Secondly, the article also research a new lower triangular decompositionsubspace extraction algorithm derived from reduced eigenvalue decompositionalgorithm.The biggest advantage of this algorithm is that it can be achieved viaQR-Givens rotation.Therefore, parallel processing by hardware can easily implemented,which provides a good basis for the next step of algorithm application.