This paper aims to provide a comprehensive scheme with limited feedback for downlink millimeter wave (mmWave) multiuser\nmultiple-input multiple-output (MIMO) nonorthogonal multiple access (NOMA) system. Based on the feedback of the best beam\nand the channel quality information (CQI) on this beam, the users are grouped into a cluster having the same or coherent best\nbeam and the maximal CQI-difference. To further reduce the intercluster interference, only the candidate cluster can join the\ncluster set whose intercluster correlation with the existing clusters is lower than threshold. Based on the results of clustering,\nmmWave hybrid beamforming is designed. To improve the user experience, each cluster selects the best beam of the user with\nthe higher guaranteed rate requirement as the analog beamforming vector. For digital beamforming, the weak user applies the\nblock diagonalization algorithm based on the strong userâ??s effective channel to reduce its intracluster interference. Finally, an\nintracluster power allocation algorithm is developed tomaximize the power difference in each clusterwhich is beneficial to improve\nthe successive interference cancelation (SIC) performance of the strong user. Finally, simulation results show that the proposed\nMIMO-NOMA scheme offers a higher sum rate than the traditional orthogonal multiple access (OMA) scheme under practical\nconditions.
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