A method of transmitting, by a user equipment, control information in a communication system. The method according to one embodiment includes multiplying transmission information corresponding to the control information by a frequency direction sequence, of which length corresponds to a number of subcarriers in a resource block, to generate a first output signal; multiplying the first output signal by a time direction sequence, of which length corresponds to a number of symbols used for transmission of the control information in a transmission unit, to generate a second output signal; and transmitting the second output signal in the transmission unit.