A method for communicating Acknowledgement/Negative acknowledgement (ACK/NACK) information in a mobile communication system, the method comprising: spreading, by a base station, the ACK/NACK information using an orthogonal sequence with a spreading factor of 4; transmitting, by the base station, a first signal including first 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 is 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 on the first set of four available neighboring subcarriers; transmitting, by the base station, a second signal including second spread ACK/NACK information on a second set of four available neighboring subcarriers in an OFDM symbol, wherein the second spread ACK/NACK information is 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 second 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 a 3 a 4 antenna B - a 2 * a 1 * - a 4 * a 3 * 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 a 1 a 2 a 3 a 4 antenna D - a 2 * a 1 * - a 4 * a 3 * wherein a 1 to a 4 are elements of the first and second spread ACK/NACK information, and the symbol * denotes a conjugate operation, 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. spreading, by a base station, the ACK/NACK information using an orthogonal sequence with a spreading factor of 4; transmitting, by the base station, a first signal including first 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 is 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 on the first set of four available neighboring subcarriers; transmitting, by the base station, a second signal including second spread ACK/NACK information on a second set of four available neighboring subcarriers in an OFDM symbol, wherein the second spread ACK/NACK information is 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 second 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 a 3 a 4 antenna B - a 2 * a 1 * - a 4 * a 3 * 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 a 1 a 2 a 3 a 4 antenna D - a 2 * a 1 * - a 4 * a 3 * wherein a 1 to a 4 are elements of the first and second spread ACK/NACK information, and the symbol * denotes a conjugate operation, 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.