5G New Radio Research Articles

The Use of Machine Learning Techniques for Optimal Multicasting in 5G NR Systems

Multicasting is a key feature of cellular systems, which provides an efficient way to simultaneously disseminate a large amount of traffic to multiple subscribers. However, the efficient use of multicast services in fifth-generation (5G) New Radio (NR) is complicated by several factors, including inherent base station (BS) antenna directivity as well as the exploitation of antenna arrays capable of creating multiple beams concurrently. In this work, we first demonstrate that the problem of efficient multicasting in 5G NR systems can be formalized as a special case of multi-period variable cost and size bin packing problem (BPP). However, the problem is known to be NP-hard, and the solution time is practically unacceptable for large multicast group sizes. To this aim, we further develop and test several machine learning alternatives to address this issue. The numerical analysis shows that there is a trade-off between accuracy and computational complexity for multicast grouping when using decision tree-based algorithms. A higher number of splits offers better performance at the cost of an increased computational time. We also show that the nature of the cell coverage brings three possible solutions to the multicast grouping problem: (i) small-range radii are characterized by a single multicast subgroup with wide beamwidth, (ii) middle-range deployments have to be solved by employing the proposed algorithms, and (iii) BS at long-range radii sweeps narrow unicast beams to serve multicast users.

Strategies For 5g Nr Networks Distribution In Rwanda

The fifth-generation mobile network has been developed and standardized with an intention of exploring the market beyond 2017. The question was to study the distribution strategies to fill out the needs of this strong network introduced for real-time feedback. Mobile operators proposed five alternative network architectures to 3GPP. The response to the question was to carry out the first distribution strategy which is Non-Standalone New Radio (NSA NR) in 2017 followed by a Standalone New Radio access network that was standardized in 2018. This study analyzes the distribution strategies of the 5G New Radio (NR) network, main technologies, benefits and drawbacks and compares NSA NR and SA NR distribution modes in terms of coverage, network capability, the inter-working which is between 4G and 5G, complexity and network distribution cost in Rwanda. This also highlights the potential challenges to implement 5G especially in Least Developed Countries. Micro Operators have been also used to accelerate the deployment for new entries and presented some challenges where the proposed solution for them has been the planification of a huge amount of economic resources as well as skilled manpower. The study concluded that the reliable and efficient distribution strategies of 5G NR Networks will be based on Non-Standalone (NSA), Standalone (SA) and the Micro Operators considerations to accelerate its distribution not only in global context but also in Rwanda

Mathematical Framework for Mixed Reservation- and Priority-Based Traffic Coexistence in 5G NR Systems

Fifth-generation (5G) New Radio (NR) systems are expected to support multiple traffic classes including enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC) at the same air interface. This functionality is assumed to be implemented by utilizing the network slicing concept. According to the 3rd Generation Partnership Project (3GPP), the efficient support of this feature requires statistical multiplexing and, at the same time, traffic isolation between slices. In this paper, we formulate and solve a mathematical model for a class of Radio Access Network (RAN) slicing algorithms that simultaneously include resource reservation and a priority-based service discipline allowing us to incur fine granularity in the service processes of different traffic aggregates. The system is based on a queueing model and allows parametrization by accounting for the specifics of wireless channel impairments. As metrics of interest, we utilize K-class session drop probability, K-class session pre-emption probability, and system resource utilization. To showcase the capabilities of the model, we also compare performance guarantees provided for URLLC, eMBB, and mMTC traffic when multiplexed over the same NR radio interface. Our results demonstrate that the performance trade-off is dictated by the offered traffic load of the highest priority sessions: (i) when it is small, mixed reservation/priority scheme outperforms the full reservation mechanism; (ii) for overloaded conditions, full reservations provides better traffic isolation. The mixed strategy is beneficial to traffic aggregates with short-lived lightweight sessions, such as URLLC and mMTC, while the reservation only scheme works better for elastic eMBB traffic. The most important feature is that the mixed strategy allows resource utilization to be improved up to 95%, which is 10–15% higher compared to the reservation-only scheme while still providing isolation between traffic types.

Analysis of a photonic integrated circuit for passive optical network for 5G NR.

This work presents the performance analysis of a passive optical network (PON) proposal with photonic integrated circuits (PIC). The PON architecture was simulated on MATLAB, focusing on the main functionalities of the optical line terminal, distribution network, and network unity regarded its effects on the physical layer. We show a simulated PIC, implemented on MATLAB through its analytic transfer function equation, used to implement orthogonal frequency division multiplexing in the optical domain to enhance the current optical networks for the 5G New-Radio (NR) scenario. We analyzed the OOK and optical PAM4 compared with phase modulation formats such as the DPSK and DQPSK. All modulation formats can be directly detected for the case in the study, simplifying the reception. Consequently, this work achieved a maximum symmetric transmission capacity of 1.2Tbps over 90km of standard single-mode fiber with 128 carriers, 64 carriers for downstream and 64 for upstream, obtained from an optical frequency comb with 0.3dB flatness. We concluded that phase modulation formats associated with PIC could increase PON capability and push further our current scenario to the 5G new era.

An Analytical Latency Model and Evaluation of the Capacity of 5G NR to Support V2X Services Using V2N2V Communications

5G has been designed to support applications such as connected and automated driving. To this aim, 5G includes a highly flexible New Radio (NR) interface that can be configured to utilize different subcarrier spacings (SCS), slot durations, scheduling, and retransmissions mechanisms. This flexibility can be exploited to support advanced V2X services with strict latency and reliability requirements using V2N2V (Vehicle-to-Network-to-Vehicles) communications instead of direct or sidelink V2V (Vehicle-to-Vehicle). To analyze this possibility, this paper presents a novel analytical model that estimates the latency of 5G at the radio network level. The model accounts for the use of different numerologies (SCS, slot durations and Cyclic Prefixes), modulation and coding schemes, full-slots or mini-slots, semi-static and dynamic scheduling, different retransmission mechanisms, and broadcast/multicast or unicast transmissions. The model has been used to first analyze the impact of different 5G NR radio configurations on the latency. We then identify which radio configurations and scenarios can 5G NR satisfy the latency and reliability requirements of V2X services using V2N2V communications. This paper considers cooperative lane changes as a case study. The results show that 5G can support advanced V2X services at the radio network level using V2N2V communications under certain conditions that depend on the radio configuration, bandwidth, service requirements and cell traffic load.

Wideband Surface Acoustic Wave Filter at 3.7 GHz With Spurious Mode Mitigation

As an essential functional block in radio frequency (RF) front-ends, surface acoustic wave (SAW) filters with large fractional bandwidth (FBW), high center frequency ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$f_{c}$ </tex-math></inline-formula> ), and low loss are highly sought-after in 5G new radio (NR). To address this end, 32°Y-X LiNbO3/SiO2/Si heterostructure with high electromechanical coupling coefficient of 23% was constructed, while the propagation characteristics as well as spurious resonance were analyzed through finite element method (FEM) and one-port resonators measurement. It is revealed that by using thin electrodes in the series resonator and thick electrodes in the parallel resonator, spurious modes are successfully eliminated out of the passband. As a result, the SAW filters formed by the above resonators are capable of several superb RF performances: a large bandwidth of 730 MHz (FBW of 19.5%) at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$f_{c}$ </tex-math></inline-formula> of 3.74 GHz, a small insertion loss (IL) of 3.03 dB, and a flat passband. Furthermore, since our devices were fabricated by standard photolithography process, this work advances commercial implementation of SAW filter in 5G NR.

On the Feasibility of Remote Driving Applications Over mmWave 5G Vehicular Communications: Implementation and Demonstration

This paper presents a study conducted for the feasibility validation of a remote driving application, which is one of the use cases of 5G Vehicle-to-everything (V2X), over millimeter-wave (mmWave) 5G New Radio (NR) vehicular communications. First, the overall network architecture of a typical mmWave 5G NR communication system and design details of essential system components for remote driving applications are provided. Then, we discuss key technologies, including beam switching, automatic gain control, uplink transmit power control, and hybrid automatic repeat request with soft combining, enabling the system to offer reliable communication links for remote driving support. Lastly, we describe the implementation and deployment of testbeds and provide the experimental results obtained from field trials. The field trial results reveal that leveraged by the key enabling technologies and mmWave providing a wider spectrum and shortened latency, the mmWave 5G NR vehicular communication system has the capability to provide broadband, reliable, and low-latency communication links for the realization of remote driving applications, which eventually paves the road towards expanding the applicability of mmWave communication systems.

Enhanced 4×4 MIMO RoF architecture for 5G mmWave indoor applications at 60 GHz unlicensed band

4×4 Multiple Input Multiple Output (MIMO) optical architecture based on Radio over Fiber (RoF) is proposed for 5G millimeter Wave (mmWave) indoor applications in the unlicensed 60 GHz band. First-order and second-order sidebands, generated by Dual-Drive Mach-Zehnder Modulator (DD-MZM), are exploited as optical subcarriers in order to reduce the number of Local Oscillators (LOs) implemented. Four MIMO-OFDM signals are multiplexed using Dual-Parallel Mach-Zehnder Modulator (DP-MZM) configured to perform Optical Carrier Suppression (OCS) modulation. 60 GHz spacing is ensured between each data signal and its corresponding subcarrier which allows simple heterodyne detection at Radio Access Point (RAP) level. In addition, we have proposed a 4×4 MIMO extension of Triple-S-and-Valenzuela (TSV) radio channel model based on geometrical approach. We demonstrate that the proposed RoF system with adequate configuration can meet the 5G New Radio (NR) requirement in terms of Error Vector Magnitude (EVM). Moreover, Bit Error Rate (BER) performance is evaluated with and without 5G NR channel coding, for transmission over 25 km of optical fiber followed by 3 m of radio channel, by exploiting the overall allocated band at 60 GHz which allows to achieve a very high data rate up to 122.5 Gb/s.

Intelligent Driver Model-Based Vehicular Ad Hoc Network Communication in Real-Time Using 5G New Radio Wireless Networks

Vehicular ad hoc networks (VANETs) are self-organizing, open-structure inter-vehicle communication networks, along with wireless communication technology and transportation. Vehicle communication aims to improve the driver’s response-ability and ensure traffic safety when encountering traffic accidents. The 5G NR on V2V communication, compared to fourth-generation (4G) long-term evolution (LTE), is more sophisticated and has ultra-high reliability. This research proposes intelligent driver model-lane changes (IDM-LC) and intelligent driver model-avoidance (IDM-A) models, which enhance the performance accuracy of the V2V communication through the 5G NR system. In this case, the authenticity of the vehicle movement models is tested on different road scenarios, i.e., square, hexagon, heptagon and triangle. In these scenarios, the vehicles’ movements over the 5G networks receive widespread coverage whenever the vehicles receive signals from the roadside unit (RSU). Hence, the flexibility of VANET is used to improve the device-to-device (D2D) or vehicle-to-vehicle (V2V) communication efficiency in the fifth-generation (5G) new radio (NR) system. In addition, the VANET simulation platform, i.e., simulation of urban mobility (SUMO) and network simulator-3 (NS-3), simulate and evaluate the comparison of V2V through the 5G networks, which receives widespread coverage in 15 to 20 m/s. The simulation results and analysis show that the V2V communication through the 5G system performs better on the IDM models.

SiGe and CMOS Technology for State-of-the-Art Millimeter-Wave Transceivers

Innovation and evolution are paramount where the demand for wideband, data-intensive connectivity is ever-increasing, and the only constant is change. Standards that define the operation of next-generation mobile networks are moving away from the traditional radio frequency (RF) spectrum and into millimeter-wave (mm-wave) bands. The physical layer (PHY) for IEEE 802.11ad Wi-Fi and 802.11ay WLANs dictates operation in the unlicensed 60 GHz band. 5G New Radio (NR) applications utilize selected bands from 26 to 39 GHz. Additionally, newly developing Fourth Industrial Revolution (4IR) applications depend on 5G NR as an enabling technology. Satellite communications and wireless backhaul will occur in E-band between 70–86 GHz. Increasing demands from the market cause designers to push boundaries, and the development of standards guide technological advances. Perhaps the most substantial improvements are observed in integrated circuit technology. This article details the major Si processes, namely Complementary Metal Oxide Semiconductor (CMOS) and SiGe Bipolar CMOS (BiCMOS), and their foray into the wireless transceiver space traditionally dominated by GaAs. CMOS and BiCMOS have become popular in many communities because of their low fabrication cost and excellent digital integration capabilities. RF performance has matured to where Si is a serious competitor for tried-and-tested III-V technologies. Some extreme environments and sophisticated applications still favor GaAs and GaN, however. GaAs, for example, can yield unparalleled output power and excellent noise figure performance, albeit at a higher cost and increased design and manufacturing complexity due to the multi-chip nature of these circuits.

Sequential Anomaly Detection Against Demodulation Reference Signal Spoofing in 5G NR

In fifth generation (5G) new radio (NR), the demodulation reference signal (DMRS) is employed for channel estimation as part of coherent demodulation of the physical uplink shared channel. However, DMRS spoofing poses a serious threat to 5G NR since inaccurate channel estimation will severely degrade the decoding performance. In this correspondence, we propose to exploit the spatial sparsity structure of the channel to detect the DMRS spoofing, which is motivated by the fact that the spatial sparsity structure of the channel will be significantly impacted if the DMRS spoofing happens. We first extract the spatial sparsity structure of the channel by solving a sparse feature retrieval problem, then propose a sequential sparsity structure anomaly detection method to detect DMRS spoofing. In simulation experiments, we exploit clustered delay line based channel model from 3GPP standards for verifications. Numerical results show that our method outperforms both the subspace dimension based and energy detector based methods.

Optimized Modulation and Coding for Dual Modulated QR Codes.

We present optimized modulation and coding for the recently introduced dual modulated QR (DMQR) codes that extend traditional QR codes to carry additional secondary data in the orientation of elliptical dots that replace black modules in the barcode images. By dynamically adjusting the dot size, we realize gains in embedding strength for both the intensity modulation and the orientation modulation that carry the primary and secondary data, respectively. Furthermore, we develop a model for the coding channel for the secondary data that enables soft-decoding via 5G NR (new radio) codes already supported by mobile devices. The performance gains for the proposed optimized designs are characterized via theoretical analysis, simulations, and actual experiments using smartphone devices. The theoretical analysis and simulations inform our design choices for the modulation and coding, and the experiments characterize the overall improvement in performance for the optimized design over the prior unoptimized designs. Importantly, the optimized designs significantly increase usability of DMQR codes with commonly used QR code beautification that cannibalizes a portion of the barcode image area for the insertion of a logo or image. In experiments with a capture distance of 15 inches, the optimized designs increase the decoding success rates between 10% and 32% for the secondary data while also providing gains for primary data decoding at larger capture distances. When used with beautification in typical settings, the secondary message is decoded with a high success rate for the proposed optimized designs, whereas it invariably fails for the prior unoptimized designs.

Multipolarization Superposition Beamforming: Novel Scheme of Transmit Power Allocation and Subcarrier Assignment

The 5th generation (5G) new radio (NR) access technology and the beyond-5G future wireless communication require extremely high data rate and spectrum efficiency. Energy-efficient transmission/reception schemes are also regarded as an important component. The polarization domain has attracted substantial attention in this aspect. This paper is the first to propose multi-polarization superposition beamforming (MPS-Beamforming) with cross-polarization discrimination (XPD) and cross-polarization ratio (XPR)-aware transmit power allocation utilizing the 5G NR antenna panel structure. The appropriate orthogonal frequency division multiplexing (OFDM) subcarrier assignment algorithm is also proposed to verify the theoretical schemes via simulations. The detailed theoretical derivation along with comprehensive simulation results illustrate that the proposed novel scheme of MPS-Beamforming is significantly beneficial to the improvement of the performance in terms of the symbol error rate (SER) and signal-to-noise ratio (SNR) gain at the user equipment (UE). For instance, a provided practical wireless channel environment in the simulations exhibits 8 dB SNR gain for 10−4 SER in a deterministic channel, and 4 dB SNR gain for 10−5 SER in abundant statistical channel realizations.

A Double-Beam Soft Handover Scheme and Its Performance Analysis for mmWave UAV Communications in Windy Scenarios

Unmanned aerial vehicles (UAVs) acting as users to access the cellular network over the millimeter wave (mmWave) spectrum form a promising solution to guarantee high data rate transmission. Due to the narrow beams in the mmWave systems and the high mobility of the UAVs, a key challenge of mmWave UAV communications is to design efficient and seamless handover schemes, especially in windy scenarios. In this paper, we first investigate the signaling interaction procedure of the hard handover strategy in 3GPP 5G new radio (NR) standard. For providing better connectivity and lower outage probability, a soft handover scheme named double-beam soft handover (DB-SH) is designed for the mmWave UAV system. Considering the dynamic wind effects, we formulate a random walk (RW) model for quantifying the angle offsets of the beams at the UAVs, as the orientations of the UAVs suffer from the fluctuations over time due to the dynamic wind load. Considering the RW model and the beam training, we further analyze the outage probabilities of the 3GPP 5G NR hard handover scheme and the DB-SH scheme for the mmWave UAV communication systems. Finally, our simulation results demonstrate the accuracy of the presented theoretical analysis which provides insights for mmWave UAV system designs.

A Survey on DRX Mechanism: Device Power Saving From LTE and 5G New Radio to 6G Communication Systems

The Discontinuous Reception (DRX) is the most effective timer-based mechanism for User Equipment (UE) power saving. In Long Term Evolution (LTE) systems, the development of the DRX mechanism enormously extends the UE battery life. With the DRX mechanism, a UE is allowed to enter a dormant state. Given a DRX cycle, the UE needs to wake up periodically during the dormancy to check whether it receives new downlink packets or not. The UE can achieve a high sleeping ratio by skipping most channel monitoring occasions. As the mobile network evolved to 5G, the battery life requirement increased to support various new services. 3rd Generation Partnership Project (3GPP) also enhances the DRX mechanism and adds new DRX-related features in the New Radio (NR) Release 16 standard. In addition to the time-based design, 3GPP proposed two signaling-based mechanisms: power saving signal and UE assistance information. This survey paper introduces the latest DRX mechanism in the 3GPP NR standard and summarizes the state-of-the-art research. Researchers have investigated the DRX mechanism in various use cases, such as Web browsing services and heterogeneous networks. They focus on the UE sleep ratio and packet delay and propose corresponding analytical models. New DRX architectures are also discussed to conquer the power-saving problem in specific schemes, especially in the 5G NR networks. This paper categorizes and presents the papers according to the target services and the network scenarios in detail. We also survey the work focusing on the new challenges (such as beamforming and thermal issue) in the NR network and introduce the future research directions in the 6G era.

Design of Compact Antenna Array for MIMO Implementation Using Characteristic Mode Analysis for 5G NR and Wi-Fi 6 Applications

In this paper, we present a compact antenna for 5G new radio (NR) and Wi-Fi 6 applications. Using characteristic mode analysis (CMA), two orthogonal modes have been separated and then a gapcoupled shaped feed-line has been used to excite the radiator. An open stub is added to achieve the wide operating bandwidth of the antenna. The size of a single antenna element and the 1×2 array-unit (AU) are 20×21.5 mm2 and 40×21.5 mm2, respectively. The operating and fractional bandwidths (FBW) of the AU are 5.18-7.71GHz and 39.25%, respectively. The proposed AU is used to develop a number of radiating element-independent multiple-input-multiple-output (MIMO) antennas comprising of 2AUs, 4AUs, and 8AUs with identical electrical characteristics and good isolation (I).18.8 dB. All the AUs have realized gain 3.0 dBi, and the total antenna efficiency 70% making it suitable for the single-user MIMO (SU-MIMO) and multiple users MIMO (MU-MIMO) needed for Wi-Fi 6 applications. To show the application of these antennas, the deployment scenario of a 16AUs MIMO antenna on a large size ground plane which mimics the smart TV panel and router chassis, etc., is also presented. These AUs may find potential applications in radiator-number independent MIMO systems.

Dual-Band MIMO Antenna with Enhanced Isolation for 5G NR Application.

A two-port multiple-input and multiple-output (MIMO) antenna with dual-band characteristics operating at the fifth-generation (5G) new radio (NR) sub-6 GHz n7/n38/n41/n79 bands is proposed. The proposed MIMO antenna is composed of two symmetric antenna elements and a defected ground plane. The antenna element consists of an incomplete circular patch with two L-shaped branches. By applying the defected ground structure and the slotted stub, the current distribution on the ground plane is changed to reduce the mutual coupling between the antenna elements. The measured -10 dB reflection coefficients cover 2.34-2.71 GHz and 3.72-5.10 GHz, while the measured isolation is larger than 20 dB at the whole operating frequency band. The paper has investigated different performance parameters in terms of the envelope correction coefficient (ECC), diversity gain (DG), radiation patterns, antenna gain, and efficiency. The proposed MIMO antenna is suitable for 5G applications.

Experimental demonstration of transport over fiber using 5G NR with performance enhancement using DPD

The article proposes an experimental implementation with a performance comparison of 5G new radio (NR) multiband waveforms utilizing analog radio over fiber (A-RoF) link equipped with performance enhancement via digital predistortion (DPD) methods. An unprecedented convolutional neural network (CNN) is compared with our earlier proposed robust methods such as deep neural network (DNN), magnitude-selective affine (MSA) and generalized memory polynomial (GMP) methods. In circumstances when deep learning is not practicable due to high complexity, we have presented an integrative lightweight convolutional neural network (ILWCNN) approach which is stable over time without the need for DPD coefficient updates. The experimental bench consists of a multiband 5G NR standard at a carrier frequency of 20 GHz with a bandwidth of 50 MHz and a flexible-waveform signal at 3 GHz with a bandwidth of 20 MHz. A 10 km of single-mode fiber is used to transport the signals modulated by a dual-drive Mach Zehnder Modulator. The paper discusses the selection of reduced complexity and robust performance of the ILWCNN-based DPD that eventually outperforms the conventional methods. The proposed ILWCNN reduces the error vector magnitude (EVM) to 1.65% as compared to 4.1%, 3.1%, 1.9% and 7.4% of EVM for GMP, MSA, DNN and non-compensated cases respectively. Similarly, the adjacent channel leakage ratio (ACLR) of −28 dBc uncompensated link is reduced with GMP, MSA and ILWCNN to −40 dBc, −45 dBc and −47 dBc respectively. The suggested ILWCNN approach outperforms the compared methods in terms of ACLR and EVM attaining the 3GPP Release 17 requirements.

A Review of Radio Frequency Based Localisation for Aerial and Ground Robots with 5G Future Perspectives

Efficient localisation plays a vital role in many modern applications of Unmanned Ground Vehicles (UGV) and Unmanned Aerial Vehicles (UAVs), which contributes to improved control, safety, power economy, etc. The ubiquitous 5G NR (New Radio) cellular network will provide new opportunities to enhance the localisation of UAVs and UGVs. In this paper, we review radio frequency (RF)-based approaches to localisation. We review the RF features that can be utilized for localisation and investigate the current methods suitable for Unmanned Vehicles under two general categories: range-based and fingerprinting. The existing state-of-the-art literature on RF-based localisation for both UAVs and UGVs is examined, and the envisioned 5G NR for localisation enhancement, and the future research direction are explored.

A Wideband Eight-Element Antenna with High Isolation for 5G New-Radio Applications

A wideband multiple-input multiple-output (MIMO) antenna with high isolation for fifth-generation (5G) new-radio (NR) smartphone employment operating at a range from 3.3–5 GHz is presented in the paper. The wideband antenna is comprised of eight identical radiation units and applies defected ground structure (DGS) to offer higher isolation between antenna units. Each of the antenna elements is formed of a C-shaped microstrip line, two triangle-shaped strips and a rectangular strip. The measurement results present that the transmission coefficients of the presented antenna are smaller than −18 dB in the required wideband, and the envelope correlation coefficient (ECC) values are better than 0.005. The realized gain and efficiency of the designed antenna are about 3.5 dBi and higher than 75%, respectively. The volume of this total antenna is 150 × 75 × 7 mm3, and the measurement of each antenna unit is merely 6.8 mm × 7 mm × 0.8 mm (0.077 λ×0.08 λ×0.009 λ, λ is the wavelength of 3.4 GHz). The presented MIMO antenna is suitable for 5G new-radio (NR) smartphone applications.