Jointly optimized transmit beamforming and temporal user scheduling in multiuser multicell scenarios based on correlation knowledge

This paper presents a new approach for a joint optimization of beamforming and temporal user scheduling for intercell interference mitigation in a multiuser multicell scenario using statistical channel knowledge. In general, the resource allocation problem considers two optimization criterions: fairness among the users in the network and a maximized sum rate of all users. The first one is achieved by a network-wide conventional multiuser transmit beamforming and the second one is achieved by an optimal assignment of users to scheduling slots. The resulting optimization problem is proven to be NP-hard, because of its equivalence to the well-known multidimensional assignment problem. A new low complexity algorithm is proposed to find good solutions with respect to the problem complexity. Regarding the performance and complexity, the new algorithm outperforms the simulated annealing technique, which is a well-known technique to overcome local optima.