First and Second Order Iterative Null Broadening Beamforming
Burak Ors, Raungrong Suleesathira · 2019
In the scattering environment, multipath occurrence causes the angular spread (AS) around the direction of arrival (DOA) at the antenna array. Forming broad nulls at the interference directions in order to cancel all paths possible and keeping a main beam in the look direction is challenged. The iterative null broadening algorithm consisted of two steps: joint estimation of DOA and AS and iterative broad null steering is proposed. The marginal MUSIC (MUltiple of Signal Classification) increases the capability of the conventional MUSIC for joint DOA and AS estimation. First and Second order iterative null broadening beamforming can steer a main beam toward the desired signal and make broad nulls in the direction of unwanted signals. The iteration is terminated by the convergence of the estimated output SINR (Signal to interference and noise ratio). According to the results, the first and second order iterative null broadening beamforming enhances the optimal beamforming and iterative optimal beamforming.