Spatial resource allocation for the multiuser multicarrier MIMO broadcast channel - a QoS optimization perspective

Solving Quality of Service constrained optimization problems in the Multiple-Input Multiple-Output (MIMO) broadcast channel usually requires the iterative solution of a weighted sum rate maximization, which exhibits a considerable amount of numerical complexity itself, especially in Orthogonal Frequency Multiplexing (OFDM) systems. In this paper a low complexity framework for these problems is presented, where the allocation of data streams to users and carriers is done successively. An efficient rule for choosing the user and carrier to be allocated in each step is presented for both linear and non-linear precoding leading to small performance losses compared to the optimum.