— Joint cooperative processing of transmitted signal from several multiple-input multiple-output (MIMO) base station (BS) antenna heads is considered for users located within a soft handover (SHO) region. Downlink resource allocation problem with different BS power constraints is studied. The mathematical framework for the SHO based MIMO system is derived and the joint design of linear transmit and receive beamformers in a MIMO multiuser transmission according to weighted sum rate maximization criterion and subject to per BS power constraints is considered. The proposed algorithm is shown to provide very efficient solutions despite of the fact that there is no guarantee of achieving the global optimum due to the non-convexity of the problem. Moreover, practical and efficient resource allocation method based on generalized zero forcing transmission is provided.
Antti Tölli, Marian Codreanu, Markku J. Juntt