An adaptive beamforming scheme for cooperative wireless networks

In this work we present an adaptive beamforming scheme for the uplink transmission of a cooperative wireless system consisted of a single antenna source, single antenna relays and a multiple antenna destination (base station). First, we present a SVD-based beamforming scheme under the assumption that perfect channel state information (CSI) is available at the transmitting nodes. Then, we develop an efficient adaptive version of this scheme which requires only partial CSI. The amount of CSI feedback is reduced by employing a prediction mechanism for the singular vectors, at both the transmitters´ and the receiver´s ends. We evaluate the performance of this system for the amplify-and-forward cooperation protocol.