Smart Small Cell with Hybrid Beamforming for 5G: Theoretical Feasibility and Prototype Results

Abstract

Abstract-In this article, we present a real-time threedimensional (3D) hybrid beamforming for fifth generation (5G) wireless networks. One of the key concepts in 5G cellular systems is the small cell network, which settles the high mobile traffic demand and provides uniform user-experienced data rates. The overall capacity of the small cell network can be enhanced with the enabling technology of 3D hybrid beamforming. This study validates the feasibility of the 3D hybrid beamforming, mostly for link-level performances, through the implementation of a realtime testbed using a software-defined radio (SDR) platform and fabricated antenna array. Based on the measured data, we also investigate system-level performances to verify the gain of the proposed smart small cell system over long term evolution (LTE) systems by performing system-level simulations based on a 3D ray-tracing tool.Index Terms-Small cell, three-dimensional (3D) hybrid beamforming, fifth generation (5G) communications.

Relationship Between Cross-Polarization Discrimination (XPD) and Spatial Correlation in Indoor Small-Cell MIMO Systems

“…where t = t . 1 The notations Φ rH and Φ rV are random initial phases, the distributions of which are uniform within (−π, +π), for the horizontal and vertical polarization combinations at the r th MS antenna. In addition, α rt and β rt are the propagation gains from copolarization and cross-polarization, and G φ,αt and G φ,βt are, respectively, the antenna gain of copolarization and cross-polarization in the direction of AoD, which is denoted as φ.…”

“…Researchers have been able to extend mobile service coverage and network capacity through their development of small-cell technology [1]. In next-generation communications, researchers are considering multiple-input multipleoutput (MIMO) techniques [2].…”

RF Lens-Embedded Massive MIMO Systems: Fabrication Issues and Codebook Design

“…For realistic performance evaluations, we modeled Veritas Hall C of Yonsei University in Korea, shown in Fig. 14(a) [14]. The BS was located at the corner of the second floor of the building with two different antennas, i.e., with/without an RF lens array.…”

Accumulate Then Transmit: Multiuser Scheduling in Full-Duplex Wireless-Powered IoT Systems

“…However, RF-enabled EH has not been widely used in practical IoT systems due to the severe propagation attenuation of RF signal power. Fortunately, with the latest breakthroughs in wireless communications, namely small cells [5], the application of large-scale antenna arrays (e.g., massive MIMO) [6] and millimeter-wave communications [7], more attentions are paid in the field of short-distance communications, which make the RF-enabled EH more feasible than before. Furthermore, the energy consumption of IoT devices will continually reduce by the advanced circuit design, which makes the harvested energy sufficient to support their operation [8].…”