Transmit antenna diversity for OFDM-based W-LANs with a priori channel state information

OFDM-based W-LAN systems employ TDD and are typically used in nearly static environments, for which it is reasonable to assume that channel state information can be acquired before transmission. If multiple antennas are provided at the transmitter side, their coefficients can be optimised based on this information. In this paper several different transmitter diversity techniques are investigated, both employing a priori channel knowledge or not. Some practical implementation aspects are also briefly analysed