Biquaternion beamspace for polarization estimation and direction finding

A biquaternion beamspace, constructed by passing the original array data through a quaternion beamformer, is proposed in this paper. Based on our biquaternion beamspace theory, the reason why the existing biquaternion MUSIC (BQ-MUSIC) estimator is not able to estimate the sources' polarization information is theoretically analyzed. From the analytical results, a new version of biquaternion beamspace MUSIC (BB-MUSIC) estimator is introduced to retrieve the sources' polarization information as well as their direction angles. Simulation results are presented to verify the correctness and efficacy of the proposed method.