面向灵巧通信卫星应用的数字多波束成形研究

Research on Digital Beamforming Technology in Satellite Communication

围绕灵巧卫星数字多波束相控阵的工程应用,针对通信卫星采用的多波束频分多址通信体制,讨论了基于多相快速傅里叶变换(Fast Fourier Transform, FFT)的数字信道化技术和基于二维FFT的数字波束成形原理,设计了一个20 MHz带宽的阵列接收模型,将接收到的不同用户的不同频率信号通过对应的子信道输出,从而实现对多路同时到达信号的实时截获、降速以及变频,并成功集成到一个2×2阵列的数字波束成形(Digital Beamforming, DBF)多波束模块中,达到了时域和空域的双重滤波效果。进一步通过Matlab、SysGen和现场可编程门阵列(Field-Programmable Gate Array, FPGA)多平台联合仿真,验证模型的准确性和有效性。仿真结果表明,在15 dB信噪比的前提下,生成的波束能够完全覆盖用户终端所在的整个区域,确保了通信的全面覆盖,且传输误码率为0。

Focusing on the engineering application of agile satellite digital multi-beam phased arrays,the discussion centers on digital channelization technology based on multi-phase Fast Fourier Transform(FFT)and digital beamforming principles based on two-dimensional FFT,specifically addressing the multi-beam frequency division multiple access communication system used in communication satellites.A 20 MHz bandwidth array receiver model was designed to process signals from different users by routing them through corresponding sub-channels,thereby enabling real-time interception,deceleration,and frequency conversion of multiple simultaneously arriving signals.This model was successfully integrated into a 2×2 array Digital Beamforming(DBF)multi-beam module,achieving dual-domain filtering effects in both the time and spatial domains.Further validation through Matlab,SysGen,and Field-Programmable Gate Array(FPGA)multi-platform simulations confirmed the accuracy and effectiveness of the model.Simulation results show that under the condition of a 15 dB signal-to-noise ratio,the generated beam can fully cover the entire area where the user terminals are located,ensuring comprehensive communication coverage,and the transmission bit error rate is zero.