Throughput Performance of HetNets using Sectorized Picocells with 3D Beamforming at 28 GHz Band in Multipath Fading Channels

Abstract

Fifth-generation (5G) New Radio (NR) with non-standalone (NSA) operation, i.e., 5G NR NSA, which enables 5G NR deployments using existing the fourth-generation (4G) mobile systems have been introduced to diffuse 5G mobile systems. With the same configuration as a heterogeneous network (HetNet), 5G NR NSA deployments combine with macrocells by 4G and picocells by 5G in the same coverage. The use of millimeter wave bands in 5G NR is expected to achieve higher data rates because the available amount of signal bandwidth is enormous. Therefore, multiband HetNets with picocells operating at millimeter wave band can increase the system capacity and/or achieve higher data rate. To compensate for the large signal path-loss due to the use of millimeter wave band, we have proposed sectorized picocells with three-dimensional beamforming (3D-BF) in HetNets. In this paper, we investigate the transmission performance of multiband HetNets with sectorized picocells with 3D-BF operating at 28 GHz band in multipath fading channels based on tapped delay line models. Using system-level computer simulations, we clarify the average and 5-percentile user throughput of the HetNet using three-sector picocells with 3D-BF operating at 28 GHz band, whose bandwidth is 10 times wider than that of the macrocell operating at 2 GHz. We also clarify that the proposed method can increase the use rate of high-order modulation scheme in the downlink modulation and coding schemes.