Trade-off of multiplexing streams in MIMO broadcast channels

A soft antenna trade-off scheme between different quality of service (QoS) groups in multiple input multiple output (MIMO) broadcast channels (BCs) is proposed. With the proposed scheme, a higher priority group takes precedence in using multiplexing streams for satisfying its QoS requirement. The number of streams allocated to each QoS group is gracefully adapted to the wireless channel conditions and QoS requirements. Numerical results demonstrate that the proposed scheme can improve the probability of QoS-guaranteed transmission while simultaneously maximizing the total throughput.