1. A method of transmitting pilots in a wireless communication system, comprising: generating a first pilot for a first transmit antenna based on a first cyclic delay; and generating a second pilot for a second transmit antenna based on a second cyclic delay larger than the first cyclic delay by at least a cyclic prefix length, wherein generating the first pilot and the second pilot comprises generating OFDM symbols that comprise pilot symbols mapped to subcarriers spaced apart by p, where p is a prime number that does not divide N FFT , and N FFT is an FFT size for the generated OFDM symbols.