Patent ID: 8774299

Claim:
A method of communicating in a mobile communication system comprising a user equipment (UE) and a base station (BS), the method comprising: transmitting, by the BS, a first signal including first spread Acknowledqement/Negative acknowledgement (ACK/NACK) information in an orthogonal frequency division multiplexing (OFDM) symbol, wherein the first spread ACK/NACK information is in a first antenna set in a form as shown in an upper half of Table 1; transmitting, by the BS, a second signal including second spread ACK/NACK information in an OFDM symbol, wherein the second spread ACK/NACK information is in a second antenna set in a form as shown in a lower half of Table 1; receiving, by the UE, a first signal including first spread ACK/NACK information in an orthogonal frequency division multiplexing (OFDM) symbol from the first antenna set of the BS; receiving, by the UE, a second signal including second spread ACK/NACK information in an OFDM symbol from the second antenna set of the BS; de-spreading, by the UE, the first spread ACK/NACK information for identifying the ACK/NACK information; and de-spreading, by the UE, the second spread ACK/NACK information for identifying the ACK/NACK information: TABLE 1 four available neighboring subcarriers the first antenna A a 1 a 2 a 3 a 4 antenna set antenna B −a 2 * a 1 * −a 4 * a 3 * the second antenna C b 1 b 2 b 3 b 4 antenna set antenna D −b 2 * b 1 * −b 4 * b 3 * wherein a 1 to a 4 are elements of the first spread ACK/NACK information, b 1 to b 4 are elements of the second spread ACK/NACK information, and the symbol * denotes a conjugate operation, wherein the first spread ACK/NACK information and the second spread ACK/NACK information carry identical ACK/NACK information, and wherein the four available neighboring subcarriers for the first spread ACK/NACK information are separated from the four available neighboring subcarriers for the second spread ACK/NACK information by a plurality of subcarriers in a frequency domain.