Method and apparatus for detecting transmission symbol using lattice-reduction matrix in multiple input multiple output (MIMO) system

A method of detecting a transmission symbol using a lattice-reduction matrix, in a system having a plurality of antennas, the method comprising:

• detecting a symbol matrix resulting from multiplying a transmission signal matrix transmitted from the plurality of antennas by an inverse function of the lattice-reduction matrix, from a reception signal matrix comprising of a plurality of reception signals received through a plurality of input/output channels from the plurality of antennas, and calculating a noise matrix by subtracting the detected symbol matrix from the reception signal matrix;
• restoring the detected symbol matrix to an original transmission symbol matrix which existed before multiplying the transmission symbol matrix by the inverse function of the lattice-reduction matrix;
• when positions of component values of the restored transmission symbol matrix are changed with respect to positions of component values of the detected symbol matrix, exchanging positions of component values of a noise matrix comprising of noise components calculated for the plurality of antennas, in correspondence to the positions of the component values of the restored transmission symbol matrix;
• and
• adding the restored transmission symbol matrix to the noise matrix in which the positions of the component values are exchanged.

An apparatus for detecting a transmission symbol using a lattice-reduction matrix in a system including a plurality of antennas, the apparatus comprising:

• a detector detecting a symbol matrix resulting from multiplying a transmission signal matrix transmitted from the plurality of antennas by an inverse function of the lattice-reduction matrix, from a reception signal matrix comprising of a plurality of reception signals received through a plurality of input/output channels from the plurality of antennas, and calculating a noise matrix by subtracting the detected symbol matrix from the reception signal matrix;
• a restoring unit restoring the detected symbol matrix to an original transmission symbol matrix;
• a post processor exchanging positions of component values of a noise matrix comprising of noise components calculated for the plurality of antennas, in correspondence to positions of component values of the restored original transmission symbol matrix, when the positions of the component values of the restored transmission symbol matrix are changed with respect to positions of component values of the detected symbol matrix;
• and
• an adder adding the restored symbol matrix to the noise matrix in which the positions of the component values are exchanged.