An integrated direct data domain beamforming algorithm

This paper presents an integrated direct data domain least square (D³LS) beamforming algorithm to solve the problems of the original D³LS such as aperture losing, high sidelobe level and only suitable for uniformly linear array (ULA). Firstly, the proposed algorithm confirm the length of each subarray according to appropriate subarray number. Then constructs the data matrix for D³LS with the use of variable phase differences between adjacent sensors and extend the suitable array type to arbitrary shape. Thirdly, the proposed algorithm confirms the null-to-null beamwidth according to the direction of the beam pattern, then presets the highest sidelobe level. The sidelobe level can be suppressed with optimization algorithm solved by the second order cone programming. The synthetic D³LS algorithm will get the effect of not only larger array aperture which deduces narrower 3 dB beamwidth, but also lower sidelobe level, still suitable for arbitrary array type. The simulation results imply that the proposed algorithm has perfect performance.