卫星移动通信系统低信噪比抗干扰数字接收机设计

针对阵列天线卫星移动通信抗干扰能力差、传播损耗大等特性，设计了一种数字波束形成技术（DBF）和扩频技术相结合的数字接收机。其中，DBF算法采用基于递归最小均方算法（RLS）的解扩重扩盲自适应波束形成算法，使用VxWorks实现权值计算，FPGA实现波束形成；扩频方式采用直接序列扩频，在FPGA中实现。仿真分析与样机测试显示，通过两项技术联合使用，在信噪比低至-45 dB条件下仍可以实现可靠通信，同时有效加强了系统抗干扰能力。

Design of an anti-interference digital receiver for satellite mobile communication systems in low SNR application

In order to improve the anti-interference ability and reduce the propagation loss for the multi-antenna satellite mobile communication,a novel digital receiver is proposed. This receiver combines the digital beamforming(DBF) technology and the spread spectrum technology. The DBF algorithm is adaptive blind beamforming based on the recursive least square(RLS) method and the despread-respread method,which is implemented by VxWorks and FPGA. The spread spectrum mode is direct sequence(DS) spread spectrum,which is implemented by FPGA. Simulation and prototype test results show that the digital receiver can ensure the reliability of satellite communication at lower signal-to-noise ratio(under -45 dB) and improve the anti-interference ability.