A transmitting method of OFDM signal includes allocating first and second channel estimation preamble signals for channel response estimation respectively to +kth and −kth subcarriers from center frequency of first OFDM signal, allocating first and second pilot signals for residual phase offset estimation respectively to +kth and −kth subcarriers from center frequency of second OFDM signal, transmitting first and second OFDM signals respectively in different time zones using at least one antenna, where, first product of complex conjugate of first channel estimation preamble signal and second pilot signal is equal to second product of second channel estimation preamble signal and complex conjugate of first pilot signal.