Patent ID: 7643567

Claim:
A method of transmitting an orthogonal frequency division multiplexing (OFDM) signal comprising: allocating a first channel estimation preamble signal and a second channel estimation preamble signal for channel response estimation respectively to a +kth subcarrier and a −kth subcarrier (k is at least one arbitrary integer) from a center frequency of a first OFDM signal; allocating a first pilot signal and a second pilot signal for residual phase offset estimation respectively to the +kth subcarrier and the −kth subcarrier from a center frequency of a second OFDM signal; and transmitting the first OFDM signal and the second OFDM signal respectively in different time zones using at least one antenna, wherein a first product of a complex conjugate of the first channel estimation preamble signal and the second pilot signal is equal to a second product of the second channel estimation preamble signal and the complex conjugate of the first pilot signal.