The Study And Implementation Based On FPGA Of Interference Suppression Of Multi-frequency DBF Receiving System

With the development of science and technology, the production and life requirement for video image acquisition system is increasing. When the image signal is received and sampled, the same frequency and different direction irrelevant interference exists in the space. The interference has a great influence on the quality of image acquisition. In order to enhance the desired signal, restrain the disturbance signal and raise the quality of received image, the interference suppression of multi-frequency DBF receiving system is researched. In recent years, the large-scale integrated circuit technology has developed rapidly. The scale of the FPGA chip is becoming larger and larger, and the cost is becoming lower and lower. The FPGA chip can complete the whole hardware and software system with a high cost performance and convenience for system upgrade. According to the application background, this paper proposes a reasonable algorithm scheme. Analyses the structure of adaptive array antenna and signal model. The MUSIC algorithm and the LMS algorithm are studied. On this basis, a FPGA implementation scheme of the multi-frequency DBF receiving system interference suppression is put forward. To separate the different frequency signals, this paper puts forward an improved multi-channel digital down conversion structure, and analyzes the performance error. The feasibility of the scheme is proved by test. The structure not only reduces the amount of data for subsequent processing, but also saves the FPGA logic resources greatly. Then, the FPGA implementation scheme of the MUSIC algorithm is proposed. The MUSIC module is divided into covariance matrix calculation module, feature decomposition module and spectrum peak search module. And the simulation and verification of each modules are made. At the same time, puts forward the FPGA implementation scheme of the LMS algorithm. Verifications are made through MATLAB and MODELSIM software co-simulation. By comparison of results, it can be seen that the design scheme is feasible. Finally, makes the system test. Tests show that images display stably, the detail is clear and the interference suppression ability is very strong.