New preamble structure for OFDM systems with multiple transmit antennas

We propose a new preamble structure for OFDM systems with multiple transmit antennas, developing design rules for it as we proceed. In regard to channel estimation, when the proposed preamble structure is used, the number of transmit antennas can be increased without restricting the number of subcarriers. Moreover, the length of the proposed preamble structure is shorter than previous works when the number of transmit antennas is greater than 4.