A UNIFORM BEAM SELECTION ALGORITHM FOR BEAMSPACE MIMO-NOMA IN MILLIMETER-WAVE COMMUNICATION SYSTEM

The concept of beamspace multiple-input multiple-out non-orthogonal multiple access (MIMO-NOMA) is able not only to reduce the number of radio frequency (RF) chains but also to increase the spectrum efficiency in the millimeter-wave (mmWave) massive MIMO communication system. However, it is difficulty to realize the existing beam selection scheme in the system since the user side will spend too much time and computation in decoding messages by performing successive interference canceller (SIC). To solve this problem, we propose a Uniform beam selection algorithm. Specifically, according to the sparsity of the beamspace channel, the users are classified into two sets firstly. Then the beams are selected uniformly by the users with the cross-correlation of the beamspace channels. The simulation results verify that not only the spectrum and energy efficiency but also the computation of the user side in the system can be improved quite a lot with the Uniform beam selection algorithm.