Patent ID: 7912680

Claim:
A direction-of-arrival estimation apparatus comprising: N sensors; a signal vector generation unit generating a signal vector v composed of N baseband signals v 1 to v N from arriving signals received from a target by the N sensors, the target transmitting the signals or reflecting the signals; a Hankel matrix generation unit setting an order of a column of a matrix at a natural number M where 1≦M and M≦(N−1)/2 and generating at least one of (N−M)×M matrices R f1 , R f2 , R b1 , and R b2 from elements v 1 to v N-1 or v 2 to v N of the signal vector, the matrix R f1 being an (N−M)×M Hankel matrix including elements v 1 to v N-1 of the signal vector and being defined by R f ⁢ ⁢ 1 = ( v 1 … v M ⋮ ⋮ v N - M … v N ⁢ ⁢ 1 ) the matrix R f2 being an (N−M)×M Hankel matrix including elements v 2 to v N of the signal vector and being defined by R f ⁢ ⁢ 2 = ( v 2 … v M ❘ ⁢ 1 ⋮ ⋮ v N - M + 1 … v N ⁢ ) the matrix R b1 being an (N−M)×M Hankel matrix including complex conjugate elements v 1 * to v N-1 * of the signal vector and being defined by R b1 =J N-M R f1 *J M where J N-M is an (N−M)×(N−M) anti-diagonal unit matrix and J M is an M×M anti-diagonal unit matrix, the matrix R b2 being an (N−M)×M Hankel matrix including complex conjugate elements v 2 * to v N * of the signal vector and being defined by R b2 =J N-M R f2 *J M where J N-M is an (N−M)×(N−M) anti-diagonal unit matrix and J M is an M×M anti-diagonal unit matrix; and an estimation unit generating a matrix R using at least one of the matrices R f1 , R f2 , R b1 , and R b2 , dividing the matrix R into two submatrices R 1 and R 2 by R=[R 1 |R 2 ] T , and estimating a direction of arrival of the arriving signal based on the submatrices R 1 and R 2 .