Research On FPGA Implementation Of Transceiver Multi-beam

Digital beamforming can control the direction and shape of the beam flexibly by controlling the amplitude and phase weighting of the array antenna.It has a wide application prospect in communication,radar,navigation and other fields.Compared with the traditional analog beamforming method,digital beamforming is easier to transmit and receive multiple beams.With the continuous improvement of digital signal processing technology and the performance of Programmable devices,more and more digital signal processing algorithms and modules can be realized in FPGA(Field Programmable Gate Array),which provides great convenience for the realization of real-time processing platforms such as communication and radar.Based on uniform planar array antenna,this thesis studies the structure and algorithm of transmitting and receiving digital multibeams,and implements them in FPGA.The main work is as follows:1.In this thesis,several digital multibeamforming algorithms are analyzed and verified by simulation.For the orthogonal projection beamforming algorithm,the simulation results show that the algorithm can realize the orthogonal multi-beam transmission and reception,and effectively reduce the mutual interference between the beams.In order to solve the problem that the error in estimation of the interference direction may lead to the problem that the zero can not be aligned with the real interference direction,two ways are used to expand the zero direction,and the broadening effect of the two methods is simulated and analyzed.For the LMS(Least Mean Square)beamforming algorithm,its effect is analyzed when the data rate is high and the parallel processing is needed.The simulation results show that the algorithm can still converge after the parallel processing,but the convergence speed is slow.2.The basic parameters of transmitting and receiving multibeams and the signal processing modules including interpolation filtering,filtering extraction,mixing and beamforming are designed.Through the analysis and comparison of the signal processing flow,the structure of intermediate frequency beamforming and multistage sampling rate transformation is adopted to reduce the resource consumption.Then,the overall structure of transmitting and receiving multibeams is simulated,which verifies the correctness of the design and lays a foundation for the implementation of FPGA in the next step.3.Each module of transmitting and receiving multiple beams is realized in FPGA.In the process of implementation,through to the structure of parallel processing,solved the problem of the high data rate can't run.By using CORDIC(Coordinate Rotation Digital Computer)algorithm,polyphase filtering and other methods to optimize the implementation structure,the resource consumption and energy consumption are reduced and the operation stability is improved.Finally,the correctness of the design is verified by functional simulation and test.