An iterative method for the maximization of the sum-rate of multicell cooperative systems

In this paper, we consider a downlink cooperative multicell Base stations (BSs) system where the BSs are coordinating their transmitted signals to communicate with Mobile Stations (MSs) and both BSs and MSs are equipped with multiple antennas. We model this multicell cooperative system under the presence of channel estimation errors and we consider a general framework where the power that is transmitted from the BSs to the MSs is not constrained to be uniform. We propose to perform a modified version of the classical ZF beamforming where we decouple the power control and beamforming processes and we derive its corresponding cooperative system sum-rate. In order to maximize the system sum-rate, we propose a “projected gradient” based iterative algorithm and we show that using our proposed algorithm as a power allocation policy leads to significantly enhance the reachable multicell cooperative system sum-rate compared to the known situation where the power of the BSs is uniformly distributed. Simulation results are given to support our claims.