Research And Realize On The Ket Techniques Of Space Time Adaptive Processing In Beidou Receiver

Nowadays, the global navigation system is developing very fast, and many countries have developed their own navigation system. The BeiDou system is the navigation system designed by china. In this situation, how to keep our navigation system out of interference is a quiet important mission. The Binary Offset Carrier(BOC) is the agreed modulation for signals of BeiDou navigation system, which is quite different from the GPS. So do researches on the anti-interference of BOC has very important significance.This dissertation is based on the project of designing an anti-interference receiver for BD navigation system. When an interference source is existed, the receiver should focuses energy in the required direction, which helps to reduce the interference. Then the SNR of the signal will increase and it will be easier to acquired and tracked.The Space-Time Adapt Processing(STAP) is the main method used in this paper. Firstly, the diagram of the STAP is given. The key technology of STAP is obtaining the coefficients of the filter, and the solving of the coefficients can be attributed to an optimization problem. The object function of this optimization problem can be determined by the power inversion algorithm, and the optimization methods are the constrained LMS algorithm and the Lagrangian function method. In the simulation result, the performance of anti-jamming of Lagrangian function method and the LMS algorithm is given. With using the Lagrangian function method, the performance of linear antenna array and circular antenna array can be compared. How the performance of anti-jamming is changing with the interference source is researched in this paper at the same time. This dissertation gives a systematic analysis on how the STAP have in fluencence on the navigation signals, The study on which is still in a blank and this article can fill this gap. In addition, the author proposes a method to determine the order of the filter in this dissertation.At last, with using the VC707 from Xilinx, the algorithm is made possible. This module can divide into three parts, and they are adaptive filter module, the covariance matrix calculation module and the coefficient calculation module. When the matrix inversion is needed, the LU decomposition is used. The method of this paper takes satisfied effect after simulation and implementation. The production of this paper has great reference value to the design of BeiDou Receive.