Patent ID: 6999378

Claim:
In an adaptive beamformer for receiving an array steering vector X from M sensors, and applying said array steering vector to N individual beamformers for generating respective beams in respective look directions, said beamformer being characterized by a constrained optimization condition expressed as Min W ⁡ ( W H . R . W ) subject to C H .W=G where W=W(v) is a concatenated array of size N.M of all beamformer weight vectors W(v), W H denotes the Hermitian transpose of W, R=R(v) is a block-diagonal concatenated noise correlation matrix, C=C(v) is a concatenated constraint matrix of size N.M×K where K is the number of constraints, and G=G(v) is a concatenated constraint gain vector of size K, the improvement comprising: a parallel blocking matrix B of size N.M×(N.M−K) for transforming said constrained optimization condition to an unconstrained parallel optimization problem condition expressed as Min W ~ ⁡ ( ( W ( 0 ) - B . W ~ ) H . R . ( W ( 0 ) - B . W ~ ) ) , ⁢ where ⁢ ⁢ W ( 0 ) = [ W 1 ( 0 ) … W N ( 0 ) ] is a concatenated fixed-beamformer array of size N.M and {tilde over (W)} is a parallel unconstrained beamformer-weights array of size (N.M−K); and a parallel distribution block for mapping said array steering vector X to a set of parallel steering vectors X i , 1≦i≦N corresponding to respective look directions of said N individual beamformers according to X i = [ 0 … 0 [ X ] 0 … 0 ] ⁢ } length ⁢ ⁢ ( i - 1 ) · M } ⁢ length ⁢ ⁢ M } ⁢ length ⁢ ⁢ N · M , such that said concatenated noise correlation matrix R may be expressed as the summation of N noise correlation matrices corresponding to steering vectors of size N.M: R = ∑ i = 1 N ⁢ ⁢ E ⁡ [ X i · X i H ] .