Combined user and antenna scheduling scheme for MIMO–OFDM networks

A combined user and antenna scheduling algorithm implementing spatial multiplexing with limited feedback is proposed for multiple-input multiple-output orthogonal frequency-division multiplexing downlink channel. Base station (BS) should be kept updated about the channel conditions of the different subcarriers of all the users present in the multiple carrier system for the achievement of efficient spectrum utilization. Hence, users convey the channel state information (CSI) in the form of signal-to-interference-plus-noise ratio (SINR) to BS. According to the proposed algorithm, each user sends an array of best SINRs corresponding to each transmit antenna. This scheme overcomes the limitations of the schemes where all the users feed only the maximum CSI to BS. All the antennas at BS are utilized to the fullest by transferring data packets for the entire duration of communication by the proposed algorithm unlike the existing scheduling schemes. The system throughput analysis for this algorithm is presented for both homogeneous and heterogeneous network. Numerical results match well with the simulation results for this two kind of networks.