Nested Beam Selection Algorithm in Beamspace Millimeter Wave Massive MIMO System

The beamspace millimeter wave (mm-wave) Massive MIMO system uses lens array antenna for transmission, which utilizes mm-wave sparsity to reduce the number of radio frequency (RF) links, and without obvious system performance degradation. In order to reduce the inter-user interference and the waste of radio frequency chain, a nested beam selection algorithm is proposed. The proposed algorithm divides the process of beam selection into several nested layers. In each nested layer, the algorithm tries its best to make user select its maximum beam, and avoiding the inter-user interference. The simulation results show that the proposed algorithm can achieve higher system sum rate than the random beam selection and maximum beam selection.