Multiple-input-multiple-output (MIMO) antenna systems can provide the spatial multiplexing gain to enhance spectrum efficiency, but they are hampered by the fact that the number of antennas in a handheld mobile device is smaller than that of a base station. To overcome this issue, the virtual MIMO techniques arrange a group of single-antenna mobile users to become a virtual multiple-antenna entity. However, existing virtual MIMO techniques are either applicable only to a small group or computationally too complex. We propose a low-complexity user scheduling for virtual MIMO with a flexible group size. In comparison with existing approaches, our results show that the proposed user scheduling for virtual MIMO can reduce the floating operations by 96% in the case of a 6 × 6 virtual MIMO system while maintaining the same throughput and fairness performance.
- Multiple-input multiple-output (MIMO)
- Proportional fairness
- Spatial multiplexing
- Virtual MIMO