Cross-Layer Technique in a Cellular MIMO-OFDM System

This paper presents a cross-layer concept with respect to a joint design of beamforming and scheduling in a cellular MIMO-OFDM-based network. Conventionally, the beamforming and scheduling processes are designed more or less independently of each other. In contrast, this paper describes a combined approach of the scheduling and beamforming procedure, with the aim to maximize the capacity and fulfill the QoS requirements for all users within the network. For the example of delay constraints, it is shown how a joint system design is beneficial to serve users with "urgent" data packets. This is accomplished by giving the scheduling unit a control over the beams to be applied, thus favorable radio channel conditions can be temporarily generated for specific users such that the associated packets are delivered in time.