Patent ID: 8107556

Claim:
An orthogonal frequency division multiplexing (OFDM) signal transmission apparatus which transmits OFDM signals by using a plurality of transmission antennas, comprising: a subcarrier setting device configured to set some of subcarriers of the OFDM signals to pilot subcarriers for transmitting pilot signals, and remaining subcarriers thereof to data subcarriers for transmitting a data signal, polarities of the pilot subcarriers differing among the transmission antennas, the pilot subcarriers each having a polarity given by s k ⁡ ( i ) = exp ⁡ ( j ⁢ ⁢ π 2 ⁢ ( k - 1 ) ⁢ i ) where s k (i) represents the polarity of each of the pilot subcarriers, j represents an imaginary unit, i represents number of each of the pilot subcarriers, and k represents antenna number of each of the transmission antennas, wherein each of the pilot subcarriers is expressed by a product of a sequence and data representing a corresponding one of the polarities.