Patent ID: 8347161

Claim:
A retransmission method of a transmitting apparatus that performs a hybrid automatic repeat request (ARQ), the retransmission method comprising: (a) encoding an initial transmission signal to be transmitted into the form of an initial transmission matrix, transmitting the initial transmission signal encoded in the form of the initial transmission matrix, and receiving a result of error checking performed on the initial transmission signal from a receiving apparatus, the initial transmission matrix corresponding to a linear dispersion code; and (b) when an error is reported about the initial transmission signal, generating a first retransmission signal by encoding the initial transmission signal into the form of a retransmission matrix and transmitting the first retransmission signal, wherein the retransmission matrix is formed of constituent elements of the initial transmission matrix but is different from the initial transmission matrix, and corresponds to a linear dispersion code having the same capacity and diversity gain as those of the initial transmission matrix, wherein the initial transmission matrix is encoded from the initial transmission signal with the linear dispersion code is obtained by, S = ∑ q = 1 Q ⁢ ⁢ ( x q ⁢ C q + x q * ⁢ D q ) (where C q and D q denote M×T complex matrices, x* denotes a conjugate complex number of a complex number x, x q denotes a symbol, and q denotes a symbol index).