Coordinated multicell beamforming with local and global data rate constraints

We propose optimization techniques for coordinated multi-cell beamforming in the presence of local users and a global user. The local users are served by only the corresponding basestation (BS) while the global user is served by multiple basestations. The global user, with the aid of multiple antennas, is able to decode multiple data streams transmitted by various transmitters through singular value decomposition of the channels at the receiver and using left dominant singular vectors as the receiver beamforming. The coordinating basestations employ semidefinite programing based transmitter beamforming and agree to perform optimum data rate split for the global user in order to minimise the transmission power.