User pairing and resource allocation for multi-antenna users in uplink multiuser MIMO system

In a multiuser multiple-input multiple-output (MUMIMO) system where users are equipped with multiple transmit antennas, user pairing and resource allocation can enormously improve cell throughput by means of spatial multiplexing and multiuser diversity. In this paper, we first establish the optimization problem of user pairing and resource allocation in the uplink of Long Term Evolution Advanced (LTE-A) system. The problem is too complex to achieve an optimal solution. We propose a suboptimal user pairing and resource allocation algorithm, which reduces the complexity by separating the process of user selection and antenna selection. Furthermore, to guarantee user fairness, the proportional fair criteria is introduced into the proposed suboptimal algorithm. The simulation results show that the suboptimal algorithm with proportional fair criteria achieves significant gains of cell throughput and better fairness compared with traditional algorithms.