Patent ID: 7844003

Claim:
A signal detection apparatus for detecting transmission signals sent from transmission antennas based on received signals received by receiving antennas, comprising: a first reordering unit configured to arrange the received signals in a first order; a first QR decomposition unit configured to decompose a channel matrix between the received signals and the transmission signals into a unitary matrix Q and an upper triangular matrix R that correspond to the first order; a first determination unit configured to determine symbol candidates of the transmission signals based on a QRM-MLD (Maximum Likelihood Detection with QR decomposition and M-algorithm) method using the received signals arranged in the first order, and using the unitary matrix Q and the upper triangular matrix R that correspond to the first order; a second reordering unit configured to arrange the received signals in a second order that is different from the first order; a second QR decomposition unit configured to decompose the channel matrix into a unitary matrix Q and an upper triangular matrix R that correspond to the second order; a second determination unit configured to determine symbol candidates of the transmission signals based on the QRM-MLD method using the received signals arranged in the second order, and using the unitary matrix Q and the upper triangular matrix R that correspond to the second order; and an output unit configured to output symbol candidates and likelihood of the transmission signals based on determination results of at least the first and the second determination units.