Beamforming of temporally broadband bandpass plane waves using two-dimensional FIR trapezoidal filters

Two new discrete-domain methods are proposed for the beamforming of two-dimensional temporally broadband bandpass plane waves using two-dimensional spatio-temporal finite impulse response filters with novel trapezoidal-shaped passbands. The first method employs a complex-coefficient two-dimensional finite impulse response filter structure having an asymmetric trapezoidal-shaped passband at baseband and achieves the minimum possible temporal sampling rate for a given temporal bandwidth. The second method employs a real-coefficient polyphase two-dimensional finite impulse response filter structure having a rectangularly-symmetric double-trapezoidal-shaped passband and requires 50% less computational complexity for the same temporal bandwidth. Experimental results have confirmed that both methods are equally capable of enhancing the desired two-dimensional temporally broadband bandpass plane waves according to their directions of arrival under severe co-channel interference and multipath fading.