Design And Implementation Of Signal Processing Submodule Of Phased Array Communication System

Phased array radar is widely used in military because of its powerful beam control ability,adaptive interference cancellation and accurate measurement of target angle.Through resource reuse,the communication function is integrated into phased array radar,which can improve the communication efficiency,concealment and anti-jamming ability,and improve the comprehensive performance of the system.Based on a phased array radar which equipped with communication function,this paper makes theoretical analysis and hardware implementation of the phased array signal processing algorithm.This paper first introduces the phased array model,and then describes the design and simulation of T/R beamforming algorithm,anti-jamming algorithm and array angle measurement algorithm.These algorithms are optimized by the application and array model of the project.In the design of T/R beamforming algorithm,the optimal beamforming is used to realize the T/R multi-beam.In the design of anti-jamming algorithm,the performances of adaptive sidelobe cancellation and generalized adaptive sidelobe cancellation are compared in detail when the sampling covariance matrix contains or does not contain the desired signal.The selection criteria of auxiliary elements are given by simulation.In the design of array angle measurement algorithm,the sum-difference beam phase comparison method is used to realize the target angle measurement,and the calculation formulas under different array inclination angles are derived.In order to unify the processing,the method of coordinate rotation is used to abstract the influence of different array inclination angles on the calculation.By the method of variable replacement,the nonlinear angle detection curve is transformed into linear angle detection curve,and the complex calculation is moved to the later stage,which greatly reduces the calculation amount of angle measurement.According to the characteristics of communication signal,every sampling point is processed for angle measurement,which greatly improves the accuracy of angle measurement.Then the paper introduces the implementation of each algorithm module on the hardware platform based on FPGA + DSP.According to the different computing requirements of each algorithm,the appropriate platform and scheme are selected.For the calculation of digital beam forming weight,this paper mainly introduces its complex interface timing.For the anti-interference algorithm,the performance comparison between DSP and FPGA is conducted,and the scheme of using improved Cholesky decomposition to realize the inversion of high-order complex matrix on FPGA is given.For angle calculation,because of its complex calculation formula,the HLS tool is used to achieve a balance between development efficiency and resource consumption.In the debugging process of the module,the problems of module function control and data synchronization between different levels are solved.For the function control,the packet format of the control data is given first,and then two schemes,soft core and finite state machine,are proposed to realize the function control.The project involves multi-channel data synchronization problems caused by cross chip and cross board transmission.This paper proposes two synchronization measures based on FIFO,and analyzes the advantages and disadvantages of the two measures.Finally,all modules are tested,and the test scheme and test results are given.