Patent ID: 8179990

Claim:
A method for transmitting a sequence of symbols S n in a multiple-input multiple-output (MIMO) network including a transmitter having a set of transmit antennas and a receiver having a set of receive antennas, comprising the steps of: representing the sequence of symbols by a vector S=[S 1 S 2 S 3 S 4 ] T of individual symbols, where T is a transpose operator; and using a coder transmitting the individual symbols as a transmit matrix is S = [ S 1 - S 2 * S 1 - S 2 * S 2 S 1 * S 2 S 1 * S 3 - S 4 * - S 3 S 4 * S 4 S 3 * - S 4 - S 3 * ] , where * is a complex conjugate, and wherein each column of the matrix S represents the symbols transmitted, and subscripts index the set of transmit antennas, wherein the receiver has a channel matrix H = ⁢ [ h 1 , 1 h 1 , 2 h 1 , 3 h 1 , 4 h 2 , 1 h 2 , 2 h 2 , 3 h 2 , 4 h 3 , 1 h 3 , 2 h 3 , 3 h 4 , 4 h 4 , 1 h 4 , 2 h 4 , 3 h 3 , 4 ] , where elements h i,j are channel coefficients from the j th transmit antenna to the i th receive antenna, wherein a received signal r is r = ⁢ HS + n = ⁢ [ h 1 , 1 h 1 , 2 h 1 , 3 h 1 , 4 h 2 , 1 h 2 , 2 h 2 , 3 h 2 , 4 h 3 , 1 h 3 , 2 h 3 , 3 h 3 , 4 h 4 , 1 h 4 , 2 h 4 , 3 h 4 , 4 ] ⁢ [ S 1 - S 2 * S 1 - S 2 * S 2 S 1 * S 2 S 1 * S 3 - S 4 * - S 3 S 4 * S 4 S 3 * - S 4 - S 3 * ] + n , where noise n is n = [ n 1 , 1 n 1 , 2 n 1 , 3 n 1 , 4 n 2 , 1 n 2 , 2 n 2 , 3 n 2 , 4 n 3 , 1 n 3 , 2 n 3 , 3 n 3 , 4 n 4 , 1 n 4 , 2 n 4 , 3 n 4 , 4 ] . further comprising: setting a received signal r = [ r 1 , 1 r 1 , 2 r 1 , 3 r 1 , 4 r 2 , 1 r 2 , 2 r 2 , 3 r 2 , 4 r 3 , 1 r 3 , 2 r 3 , 3 r 3 , 4 r 4 , 1 r 4 , 2 r 4 , 3 r 4 , 4 ] , and the first symbol S 1 is [ r 1 , 1 ⁢ ⁢ r 1 , 2 * ⁢ ⁢ r 1 , 3 ⁢ ⁢ r 1 , 4 * ] ⁡ [ h 1 , 1 * h 1 , 2 h 1 , 1 * h 1 , 2 ] + [ r 2 , 1 ⁢ ⁢ r 2 , 2 * ⁢ ⁢ r 2 , 3 ⁢ ⁢ r 2 , 4 * ] ⁡ [ h 2 , 1 * h 2 , 2 h 2 , 1 * h 2 , 2 ] = 2 ⁢ (  h 1 , 1  2 +  h 1 , 2  2 +  h 2 , 1  2 +  h 2 , 2  2 ) ⁢ S 1 * + n 1 ′ the second symbol S 2 is [ r 1 , 1 ⁢ ⁢ r 1 , 2 * ⁢ ⁢ r 1 , 3 ⁢ ⁢ r 1 , 4 * ] ⁡ [ h 1 , 2 * - h 1 , 1 h 1 , 2 * - h 1 , 1 ] + [ r 2 , 1 ⁢ ⁢ r 2 , 2 * ⁢ ⁢ r 2 , 3 ⁢ ⁢ r 2 , 4 * ] ⁡ [ h 2 , 2 * - h 2 , 1 h 2 , 2 * - h 2 , 1 ] = 2 ⁢ (  h 1 , 1  2 +  h 1 , 2  2 +  h 2 , 1  2 +  h 2 , 2  2 ) ⁢ S 2 + n 2 ′ the third symbol S 3 is [ r 3 , 1 ⁢ ⁢ r 3 , 2 * ⁢ ⁢ r 3 , 3 ⁢ ⁢ r 3 , 4 * ] ⁡ [ h 3 , 3 * h 3 , 4 - h 3 , 3 * - h 3 , 4 ] + [ r 4 , 1 ⁢ ⁢ r 4 , 2 * ⁢ ⁢ r 4 , 3 ⁢ ⁢ r 4 , 4 * ] ⁡ [ h 4 , 3 * h 4 , 4 - h 4 , 3 * - h 4 , 4 ] = 2 ⁢ (  h 3 , 3  2 +  h 3 , 4  2 +  h 4 , 3  2 +  h 4 , 4  2 ) ⁢ S 3 + n 3 ′ .