Patent ID: 8787421

Claim:
A method for communicating Acknowledgement/Negative acknowledgement (ACK/NACK) information in a mobile communication system, the method comprising: transmitting, by a base station, a first signal including first spread ACK/NACK information and second spread ACK/NACK information on a first set of four available neighboring subcarriers in an orthogonal frequency division multiplexing (OFDM) symbol, wherein the first spread ACK/NACK information and the second spread ACK/NACK information are coded on the first set of four available neighboring subcarriers as shown in Table 1; receiving, by a terminal, the first signal including the first spread ACK/NACK information and the second spread ACK/NACK information on the first set of four available neighboring subcarriers; transmitting, by the base station, a second signal including third spread ACK/NACK information and fourth spread ACK/NACK information on a second set of four available neighboring subcarriers in an OFDM symbol, wherein the third spread ACK/NACK information and the fourth spread ACK/NACK information are coded on the second set of four available neighboring subcarriers as shown in Table 2; and receiving, by the terminal, the second signal including the third spread ACK/NACK information and the fourth spread ACK/NACK information on the second set of four available neighboring subcarriers, TABLE 1 First set of four available neighboring subcarriers in an OFDM symbol antenna A a 1 a 2 b 1 b 2 antenna B −a 2 * a 1 * −b 2 * b 1 * antenna C 0 0 0 0 antenna D 0 0 0 0 TABLE 2 Second set of four available neighboring subcarriers in an OFDM symbol antenna A 0 0 0 0 antenna B 0 0 0 0 antenna C c 1 c 2 d 1 d 2 antenna D −c 2 * c 1 * −d 2 * d 1 * wherein a 1 to a 2 are elements of the first spread ACK/NACK information, b 1 to b 2 are elements of the second spread ACK/NACK information, c 1 to c 2 are elements of the third spread ACK/NACK information, d 1 to d 2 are elements of the fourth ACK/NACK information, and the symbol * denotes a conjugate operation, wherein the first spread ACK/NACK information and the third spread ACK/NACK information carry first ACK/NACK information, wherein the second spread ACK/NACK information and the fourth spread ACK/NACK information carry second ACK/NACK information, and wherein the first set of four available neighboring subcarriers is separated from the second set of four available neighboring subcarriers by a plurality of subcarriers in a frequency domain.