Patent ID: 7702027

Claim:
A data transmission method for a transmission apparatus for transmitting a plurality of data sequences from a plurality of transmission antennas to a plurality of reception antennas using MIMO-OFDM, the method comprising: dividing a synchronization symbol in which predetermined amplitudes and phases are assigned to a plurality of subcarriers which are spaced at predetermined frequency intervals and are orthogonal to each other, into the plurality of transmission antennas, to generate a plurality of synchronization subsymbols; modulating a plurality of pieces of transmission data to be transmitted from the plurality of transmission antennas into a plurality of data symbol sequences; generating propagation coefficient estimation symbols, that are orthogonal to each other, between each of the transmission antennas as symbols for estimating inverse functions of propagation coefficients possessed by a plurality of transfer paths between the transmission antennas and the reception antennas; multiplexing the data symbol sequences, the synchronization subsymbols, and the propagation coefficient estimation symbols into a transfer frame for each of the plurality of transmission antennas; and converting the transfer frames multiplexed for the plurality of transmission antennas into radio signals; and simultaneously transmitting the radio signals from the plurality of transmission antennas, wherein, in said simultaneously transmitting, a plurality of different transmission local oscillators are used for the plurality of transmission antennas, respectively.