Abstract
Based on the minimizing mean square error (MSE) criterion, a reference signal based distributed beamforming scheme with associated adaptive algorithms is proposed. A key advantage with this scheme is that each relay node can work effectively based on only its own channel state information (CSI) and achieve a globally optimum solution without any approximation. An unconstrained adaptive algorithm is first derived and then the case with signal transmission power constraint for each individual relay node is considered. The effectiveness of the proposed scheme is verified by extensive computer simulations.