Signal separation device and signal separating method

A signal separation device used in a radio communication system in which a signal transmitted from a plurality of transmit antennas are received by a plurality of receive antennas, the signal separation device comprising:

• a column switching unit configured to switch a column vector of a channel matrix, as obtained by estimating a propagation path characteristic between each of the plurality of transmit antennas to each of the plurality of receive antennas, so that a transmitted signal component of each of the plurality of transmit antennas is in a left end;
• a QR decomposition layering unit configured to multiply a received signal of the plurality of receive antennas by an output from the column switching unit, and to output a received signal vector in which the received signal is layered so that a transmitted signal exists in a first row;
• an interference cancellation unit configured to cancel an interference component from a signal in the first row in the layered received signal vector by using a signal other than the signal in the first row in a layered received signal vector;
• a signal candidate point selecting unit configured to select a prescribed number of signal candidate points of the transmitted signal from among signals whose interference components have been cancelled;
• and
• a signal separation unit configured to perform signal separation of the transmitted signal from the layered received signal vector output by the QR decomposition layering unit by using the selected signal candidate point of the transmitted signal.