子空间投影后波束形成的导航接收机抗干扰性能分析

利用导航信号淹没于干扰信号和热噪声的特点，将天线阵列接收的空时信号矢量向干扰子空间的正交子空间投影以实现干扰抑制。当接收机对投影后的单阵元数据捕获成功后，利用捕获估计的本地扩频码相位作为参考信号，依据最小均方误差准则进行波束形成。仿真结果表明该抗干扰算法在零陷强干扰的同时使主波束指向导航信号来波方向，有效提高了阵列输出信干噪比，并降低了空时自适应处理对导航信号伪码相关峰形状和载波跟踪性能的影响。
Considering that the global navigation satellite system signal is buried in the strong interference and thermal noise, a novel anti-jamming scheme which utilizes subspace projection and beamforming method was proposed. The data vector received by antenna array was projected onto the noise subspace which is orthogonal to interference subspace to achieve interference suppression. When the local code was synchronized with the reference antenna jammer-free data, beamforming was performed according to the minimum mean square error criterion. Simulation results show that the proposed method can steer the main beam to the direction of global navigation satellite system signal wave with effective interference suppression, and the output signal-to-noise ratio can be significantly increased while the correlation peak curve and the carrier tracking performance are not corrupted.