Abstract: A new adaptive user scheduling was proposed to solve the multi-user scheduling problem of millimeter wave multi-user multiple-input single-output (MU-MISO) downlink system, in which users are located in the finite areas. Firstly, the area's user will be grouped based on the access information of user, and then the radio frequency chain will be properly allocated for each area based on the user density. Secondly, based on the RF's number and the range of angle of departure of each area, the communication beams will be designed. Finally, the best matched user will be selected to each pre-designed random beam for minimum inter-interference of beams in the base station, based on the channel quality indicator and the channel state information (CSI) feedback only from the matched users. It is shown that, the proposed scheme can achieve good rate performance. Although there is a certain gap compared with the semi-orthogonal user selection with zero-forcing beamforming that requires full CSI feedback from all users, it reduces feedback overhead to some degree. Moreover, the allocation of RF resources guarantees the fairness of user communication to a certain extent.

Key words: millimeter wave, user scheduling algorithm, zero-forcing precoding