Embodiments of the present invention may provide an apparatus and a method for transmitting and receiving a random access channel (RACH) in a single carrier-frequency division multiple access (SC-FDMA) system. A frequency domain RACH signal may be mapped to a localized sub-frequency band of an entire frequency band available to the SC-FDMA system. A guard band including at least one sub carrier may be allocated between the RACH signal band and other channel signal bands. A guard time may be allocated between the RACH signal and other channel signals in the time domain. The RACH signal may include a short message including information related to a mobile station. The RACH signal may be detected in a frequency based method, a time based method or a sliding matched filter based method. Receiver complexity can be decreased if the RACH signal includes a CAZAC code sequence for a preamble. In such a case, a receive delay may be simply calculated and then adjusted more accurately.