Research And Implementation Of Multichannel Beidou Adaptive Anti-jamming Digital Module

Global satellite navigation system shows the more and more important role in modern life, military, scientific and technological development, the related technology and products are used in various industries gradually, and it attracts the attention and research of many countries worldwide. In order to ensure the satellite navigation system with the normal use in the increasingly complex electromagnetic environment and the deliberate interfere of the military, many countries have begun to study the satellite navigation system anti-jamming technology and its related products. Beidou navigation system starts late, in order to obtain autonomy and security of global satellite navigation system, the further study of Beidou navigation system and anti-jamming technology is of great significance. In this paper, based on array antenna technology to achieve the Beidou system anti-jamming is the subject to research, focusing on designing a hardware platform based on array signal processing anti-jamming algorithms, and achieving the Beidou navigation system anti-jamming with power inversion algorithm on the hardware platform, specific research is divided into four parts:1) This paper uses the two-dimensional space-time structure, applies power inversion algorithm, establishes a broadband array antenna receive model, generates the array received simulation signals and simulates the common LMS algorithm and SMI algorithm for comparison, determines a reasonable and effective two-dimensional space-time structure. The simulation results is that the SMI algorithm has better robustness and performance of anti-jamming.2) According to the existing product parameters of the RF front-end module and satellite navigation receiver, this paper designs a digital baseband circuit board. The baseband circuit board includes AD, DA circuits, FPGA and associated circuitry, DSP and associated circuitry, clock module and power module. Detailed study of the applicability of the digital baseband board for Beidou system anti-jamming algorithm is shown, and the paper gives detailed design and principles of each part of the circuit,analyzes the system resource consumption, performance parameters and power consumption.3) The paper completes a two-dimensional space-time adaptive anti-jamming hardware implementation based on SMI algorithm.And it describes detailedly theprinciple and implementation process, including the use of FPGA to complete signal conditioning process with generating no DC component complex analytic signal; using a state machine to control multiply-accumulate unit to complete the estimation process of autocorrelation matrix and cross-correlation vector; completing the communication between FPGA and DSP by UPP interface, and correct reception of adaptive filter weight vector; solving the Hermite positive definite matrix equations in DSP, realizing the weight calculation; finally obtaining the filtered output in FPGA. Through software simulation, it is ensured that the implementation is correct.4) The paper completes the testing work of baseband digital board, the test results are given to verify that the design of the circuit board is correct; through field experiments, tests the anti-jamming performance of the system to verify the validity of the algorithm and gives the test results.