Aspects of multiuser MIMO for cell throughput maximization

We consider a multiuser MIMO downlink scenario where the resources in time, frequency and space are allocated such that the total cell throughput is maximized. This is achieved by exploiting multiuser diversity, i.e. the physical resources are allocated to the user with the highest SNR. We assume perfect channel knowledge at the transmitter which may be obtained from estimation of the uplink signal in a TDD system or from a feedback from the receiver. In this paper, we do not give mathematical details on the proposed algorithm. We rather provide an illustrative view on the principle idea. The potential for cell throughput improvement is demonstrated by capacity results based on measured channels in a large office environment. Finally, video streaming is used as a potential application with high data rate and low latency demands. It is shown that the proposed method has the potential to exploit multiuser diversity while still providing stable video streams even though QoS constraints are not explicitly taken into account by the scheduler.