Abstract: A channel estimation method in a wireless communication system based on multicarrier-code division multiple access (MC-CDMA) using frequency interleaving. A transmitter generates transmission symbols using a pilot signal (P) and an inverted pilot signal (?P) according to subcarriers on which spread symbols generated from a spectrum spreading operation are sent, performs an interleaving operation for the transmission symbols in a frequency domain, and transmits a result of the interleaving operation. A receiver extracts the pilot signal (P) and inverted pilot signal (?P) included in the transmission symbols and performs channel estimation.