Analysis of a New MIMO Broadcast Channel Limited Feedback Scheduling Algorithm with User Grouping

In this paper, we present and analyze a new multiuser multiple-input multiple-output (MU MIMO) broadcast channel scheduling algorithm with limited feedback and user grouping. Here signal-to-noise-plus-interference-ratio (SINR) feedback is used for the scheduling criteria. The algorithm deals with the following three scenarios: (a) All transmit antennas are active. (b) Receive antennas at the mobile station (MS) with maximum SINR values are assigned to the transmit antennas at the base station (BS). (c) A given receive antenna is not scheduled for more than one BS transmit antenna, which ensures user fairness. A detailed comparison of the proposed algorithm with the limited feedback antenna selection algorithms proposed by Zhang et al. and Sharif et al. is presented. Further, we have extended the proposed algorithm to heterogeneous environment, where users having similar signal-to-noise-ratio (SNR) are grouped together. Also, we evaluate the effects of sending the beamforming data (here indices of the receiving antennas) to the BS in terms of complexity of MS and feedback load ratio. A detailed analytical approach for throughput of the system is presented in this paper for the proposed algorithm. We also verify the simulation results with the analytical results.