Transmit Beamforming in Cooperative Networks

Cooperative relay communication systems has been extensively studied in recent years due to their ability to provide more reliable communications through enhanced diversity and to extend the range of the communication system. Equipping communication terminals with multiple antennas have similar advantages. In this paper, we look at a cooperative diversity system where the source node is equipped with multiple antennas. Assuming that the channel state information is available, we derive the optimal beamforming vector to maximize the capacity of the system. We will compare the optimal beamforming solution with a partially optimized solution. We will also investigate the impact of multiple relay nodes and increasing the available antennas at the source on the performance of the system.