transmission symbols received from corresponding transmission antennas using a maximum likelihood decoding method with respect to a received signal corresponding to each of the sub channel matrices estimating transmission symbols received from the remaining transmission antenna using the estimated transmission symbols temporarily storing a candidate symbol set composed of the estimated transmission symbols and comparing candidate symbol sets corresponding to all the sub channel matrices and determining the smallest candidate symbol set as a transmission symbol set application_number US 50728506 A description preferred embodiments of the present invention will now be described in detail with reference to the annexed drawings in the following description a detailed description of known functions and configurations incorporated herein has been omitted for conciseness an mimo system including n t transmission antennas and n r reception antennas to which a signal detection method according to the present invention is applied is expressed as equation 1 where x i indicates a transmission signal transmitted from an i th transmission antenna where i 1 2 n t y i indicates a reception signal received from an i th reception antenna where i 1 2 n r and z i u02dc n 0 u03c3 z 2 indicates a gaussian noise i 1 2 n r herein n 0 u03c3 z 2 is a normal distribution of which the average is u201c 0 u201d and the standard deviation is u03c3 2 on the assumption that x i is an m qam m order quadrature amplitude modulation signal a maximum likelihood ml can be expressed as follows using equation 2 for an exhaustive search m n t combinations for a transmission symbol should be considered theorem 1 necessary and sufficient condition to calculate an ml maximum likelihood solution in a linear system.