Patent ID: 7982670

Claim:
A method for determining the direction of arrival of at least one radio waveform (w a ), comprising the steps of: receiving at least one waveform (w a ) by M receiving elements ( 1 , 2 , 3 , 4 . . . ), M being a natural number and M>1, and obtaining one detected signal (d i , d 2 , d 3 , d 4 . . . ) at the output of each of the M receiving elements ( 1 , 2 , 3 , 4 . . . ); processing said M detected signals (d i , d 2 , d 3 , d 4 . . . ) at M pre-processing units ( 30 , 31 , 32 , 33 . . . ) for obtaining M processed signals (f 1 , f 2 , f 3 , f 4 . . . ); sampling at N time instants said M processed signals (f 1 , f 2 , f 3 , f 4 . . . ) at a signal processing unit ( 40 ), N being a natural number, for obtaining corresponding sample values; from the sample values obtained in the previous step, creating N column vectors y( 1 ), . . . , y(N), wherein y(n) represents, for a sampling instant n, a column vector with M rows, each of the M rows containing the sample value associated to the corresponding receiving element ( 1 , 2 , 3 , 4 . . . ) at that sampling instant n; from the collection of N column vectors y( 1 ), . . . , y(N), calculating a sample spatial correlation matrix {circumflex over (R)}; obtaining all the eigenvectors ê k , where k=1 . . . M, and all the eigenvalues {circumflex over (λ)} 1 ≦{circumflex over (λ)} 2 ≦ . . . ≦{circumflex over (λ)} M from said sample spatial correlation matrix {circumflex over (R)}; the method being characterised in that it further comprises the steps of: from all the eigenvectors ê k and all the eigenvalues {circumflex over (λ)} 1 ≦{circumflex over (λ)} 2 ≦ . . . ≦{circumflex over (λ)} M obtained in the previous step, obtaining a set of signal dependent parameters μ k , where k=1 . . . M; from the eigenvalues {circumflex over (λ)} 1 ≦{circumflex over (λ)} 2 ≦ . . . ≦{circumflex over (λ)} M and the signal dependent parameters μ k previously obtained, constructing a set of weights; finding K solutions from a certain cost function such that said K solutions fulfil a certain requirement.