增强伪自协方差矩阵直接数据域波束合成

Novel direct data domain approach beamforming using enhanced pseudocovariance matrix

对各天线单元方向图相同且均为全向天线的N元均匀线阵,直接数据域波束合成中已有方法存在着孔径损失,为克服此缺陷,提出一种基于增强伪自协方差矩阵的直接数据域波束合成新方法。将天线阵扩展为一个新的实-虚2 N元均匀线阵,建立新2 N元阵列的导向向量的伪自协方差矩阵和数据向量的伪自协方差矩阵,通过阵列扩展,增加伪自协方差矩阵的秩和阵列自由度,以消除直接数据域波束合成中已有方法存在的孔径损失。仿真表明,由于新方法没有孔径损失,采用新方法合成的波束增益更高,输出信号的信噪比更大。

For a uniform linear array with N isotropic omni-direction antenna elements,an enhanced direct data domain approach （DDDA ）beamforming is presented to reduce aperture losses in the former DDDA method.In this new method,the array is firstly extended to a new real-virtual uniform linear array with 2N elements.The pseudocovariance matrices of the data vector and the steering vector of the new 2N elements array are then formed.By expanding the array,the rank of pseudocovariance and the degree of freedom of the array are all increased to reduce aperture losses of the past DDDA method.Simulation results illustrate the higher output signal to noise ratio can be obtained due to no aperture losses in the new method,and the beam formed by the new method has the higher gain.