Multiple antenna arrays for transmitter diversity and space-time coding

Communicating reliably over the wireless fading channel is a significant challenge. Previous work has focused on exploiting the plurality of antennas available at the basestation for transmit diversity. As the forward channel is not typically known, transmit diversity schemes couple energy into the spatial channel without regard to the interference created towards cochannel users in other cells. To alleviate these problems we present a transmit diversity technique which uses strategically placed sets of antenna arrays and partial channel knowledge to direct multiple beams from different spatial locations to each user. Beamforming on each antenna array is used to achieve lower crosstalk among users while the presence of multiple arrays provides diversity benefit. Analysis of the proposed system using the pairwise error probability is presented along with simulations assuming perfect channel knowledge at the receiver