Compass / Gps Dual-mode Receiver Adaptive Antenna Array Of Anti-jamming Technology And Realization

On April 15,2009,the second BD-2 navigation satellite had been launched successfully.It indicates that China is accelerating into the ranks of great powers in satellite navigation filed.This paper's study is carried out based on the background of that.Tne dual-mode navigation receiver compatible with GPS and Beidou 2 is a trend in the military and civilian navigation filed.In terms of reliability of the system or positioning accuracy,the dual-mode navigation receiver has advantages. But in the face of the threat of interference signal that comes from the enemy's satellites or electronic warfare aircraft,the navigation receiver needs to adopt effective anti-interference technology to ensure system reliability.Through the analysis of the various kinds of interference for the navigation receiver,this paper proposed the ideas to achieve interference suppression, improve SNR of the navigation receiver by the use of airspace filter technology based on array antenna,and established a set of anti-jamming strategies by jointing mode switching with airspace filter based on the dual-mode- navigation receiver.In these anti-jamming strategies,DOA estimation algorithm is one of the key. This paper finished the theoretical derivation and simulation by using Matlab for non-coherent interference source signal DOA estimation algorithm,and come to the conclusion that Root MUSIC algorithm is suitable for the realization of the project. In the face of multi-path transmission phenomena of interference signal,this paper presents the joint DOA estimation algorithm by using of fourth-order cumulant algorithm + before-after spatial smoothing algorithm + MUSIC algorithm.The joint DOA estimation algorithm effectively solutes the problem that the MUSIC algorithm failures to work for multi-path signal.In this paper,a detailed theoretical analysis is given,at the same time is also given a great deal of visual simulation.In the realization of the project of the DOA estimation algorithm,as a result of it was hard to direct large-scale complex matrix operation in the FPGA.Therefore the application of maturity is achieved in the DSP,which is inefficient and slow because of the frame of DSP IC.The Bottlenecks mainly concentrated in computation of the complex singular value decomposition(CSVD).This paper presents an algorithm to achieve CSVD in the FPGA,finished a joint simulation of hardware and software based on the topdown thinking that is from the algorithm model directly to the hardware implementation by using the in-the-loop simulation platform,and verified the results of the algorithm.