Patent ID: 8891693

Claim:
A signal processing method for a wireless communication system including a transmitter which transmits a wireless signal using M transmission antennas and a receiver which receives the wireless signal using N reception antennas, M and N individually being integers equal to or greater than two, the signal processing method comprising: performing QR decomposition of a channel matrix between the transmitter and the receiver into products of an orthogonal matrix Q and an upper triangular matrix R; calculating products Q H y of Q H which is Hermite conjugate of the orthogonal matrix Q and a reception column vector y including N reception signals received by the receiver as component elements; calculating a signal corresponding to a component element of an Mth row of a transmission column vector x, which includes M transmission signals as component elements, based on the calculated products Q H y and the upper triangular matrix R; selecting a plurality of transmission signal candidates regarding the component element of the Mth row of the transmission column vector x which are ranked in response to an inter-signal point distance with the signal calculated on a constellation by carrying out a region decision on the constellation regarding the calculated signal; selecting a number of transmission signal candidates corresponding to predetermined parameters based on inter-signal point distances between the plurality of transmission signal candidates and signals corresponding to component elements of the (M−1)th to 1st rows of the transmission column vector x from the plurality of transmission signal candidates regarding the component elements of the (M−1)th to 1st rows of the transmission column vector x by carrying out a region decision on the constellation regarding the signals based on the calculated products Q H y, the upper triangular matrix R and the selected plurality of transmission signal candidates; and reproducing the M transmission signals by determining a unique set of the transmission signal candidates regarding the component elements of the Mth to 1st rows of the transmission column vector x based on the sum total of the inter-signal point distances between the selected transmission signal candidates and the signals corresponding to the component elements of the (M−1)th to 1st rows of the transmission column vector x, wherein the predetermined parameters include: a ratio between an average value of the sum totals of the inter-signal point distances and a diagonal component element of the upper triangular matrix R; or a ratio between a diagonal component element of the (M−1)th row of the upper triangular matrix R and a diagonal component element of the Mth row of the upper triangular matrix R.