Research And Implementation Of Adaptive Beam-forming Algorithms

As an emerging product of array signal processing technology,adaptive beam-forming is widely used in communications,radar,radio astronomy,seismic exploration,sonar,electronic countermeasures and other fields.Adaptive beam-forming technology can receive signals in a specific direction in space and prevent signals from other directions entering the system to cause interference.It has the effect of spatial filtering.In wireless communication systems,adaptive beam-forming can improve spectrum utilization and expand signal capacity.With the explosive growth of wireless communication demand and the rapid development of wireless communication technology,5G communication technology will soon enter the commercial arena.In the future,intelligent devices will work in more complex electromagnetic environment.Adaptive beam-forming technology will be an essential technology for 5G communication.Adaptive algorithm is the core technology of adaptive beam-forming.In this thesis,adaptive beam-forming algorithm is studied.Aiming at the research and analysis of adaptive beamforming algorithm,a new variable step size LMS algorithm is proposed to improve the shortcomings of the existing algorithm,and experiments are carried out in practical engineering applications.The main contents and innovations are as follows:Firstly,this thesis summarizes the current research status of adaptive beam-forming,and introduces the basic principles of adaptive beam-forming.Several commonly used adaptive criteria are analyzed,and the criteria are discussed in detail.The formulas are derived in detail and the characteristics of the criteria are summarized and compared.Secondly,several adaptive beam-forming algorithms are compared in this thesis.The least mean square algorithm is mainly studied,and the algorithm is analyzed and simulated.In view of the contradiction between convergence speed and steady-state error of fixed-step LMS algorithm,this thesis proposes a new variable-step LMS algorithm based on the existing variable-step LMS algorithm,which improves the shortcomings of the existing LMS algorithm.The simulation results show that the improved variable step size LMS algorithm can achieve faster convergence speed and smaller convergence error than the traditional LMS algorithm.Thirdly,this thesis establishes a test platform based on practical application.The LMS algorithm is implemented on the hardware platform based on DSP and FPGA.A data acquisition module based on HMCAD1520 is designed.The program of each function module in FPGA and the algorithm program of DSP are designed and tested.The validity of the proposed algorithm in practical engineering application and the functionality of the designed hardware platform are verified through measurement.Finally,the research and experimental works are summarized.Some poorly considered aspects in the thesis are pointed out.The future development direction and direction of smart antenna and adaptive beam-forming technology are prospected.