5G New Radio Research Articles

A Multiband/Multistandard 15–57 GHz Receive Phased-Array Module Based on 4 × 1 Beamformer IC and Supporting 5G NR FR2 Operation

This work presents a 15&#x2013;57 GHz multiband/ multistandard phased-array architecture for the fifth-generation (5G) new radio (NR) frequency range 2 (FR2) bands. An eight-element phased-array receive module is demonstrated based on two four-channel wideband beamformer chips designed in the SiGe BiCMOS process and flipped on a low-cost printed circuit board. The SiGe Rx chip employs RF beamforming and is designed to interface to a wideband differential Vivaldi antenna array. Each channel consists of a low-noise amplifier (LNA), active phase shifter with 5-bit resolution, variable gain amplifier (VGA), and differential-to-single-ended stage. The four channels are combined using a wideband two-stage on-chip Wilkinson network. The beamformer has a peak electronic gain of 24&#x2013;25 dB and a 4.7&#x2013;6.2 dB noise figure (NF) with a &#x2212;29 to &#x2212;24 dBm input <inline-formula> <tex-math notation="LaTeX">$P_{\boldsymbol {1\,dB}}$ </tex-math></inline-formula> at 20&#x2013;40 GHz. The eight-element phased-array module also achieved ultra-wideband frequency response with flat gain and low-system NF. The phased array scans &#x00B1;55&#x00B0; with <inline-formula> <tex-math notation="LaTeX">$ &lt; -12$ </tex-math></inline-formula>-dB sidelobes demonstrating multiband operation. A 1.2-m over-the-air (OTA) link measurement using the eight-element Rx module supports 400-MHz 256-QAM OFDMA modulation with &#x003C; 2.76&#x0025; error vector magnitude (EVM) at multiple 5G NR FR2 bands. To the author&#x2019;s knowledge, this work achieves the widest bandwidth phased array enabling the construction of multistandard systems.

Enhancements on Type-II 5G New Radio Codebooks for UE Mobility Scenarios

This article focuses on potential enhancements of current 5G New Radio (NR) codebooks (CBs) for user equipment (UE) mobility scenarios. An overview of the incremental evolution of the 5G NR Type-II CBs is presented, and its inherent drawbacks in mobility scenarios are discussed. The current Type-II CBs fail to deliver adequate performance when used by moving UEs at medium to high speeds, mainly due to the current channel coherence time-based CSI measurement and reporting. Measured channel data from a number of real-world scenarios are analyzed by means of Doppler power spectrum and delay-Doppler power spectrum to verify the so-called channel stationarity time, which is several-fold higher than the channel coherence time. Based on the presented analysis, conclusions are drawn that for stationarity time-based CSI measurements and reporting, Doppler frequency components in addition to space and delay components can be exploited for Type-II CB enhancements. The enhanced Type-II CB achieves a drastic feedback reduction due to the sparse nature of the channel in the delay-Doppler domain and improved performance compared to the 5G NR Type-II CB.

Low-Complexity Multi-Size Circular-Shift Network for 5G New Radio LDPC Decoders.

This paper presents a low-complexity multi-size circular-shift network (MCSN) structure for 5th-generation (5G) New Radio (NR) quasi-cyclic low-density parity-check (QC-LDPC) decoders. In particular, a fine-coarse approach-based multi-size cyclic shift network, which decomposes the cyclic shift size into fine part and coarse part, is introduced. The proposed MCSN structure is composed of a pre-rotator performing the fine part of the cyclic shift, and a main rotator executing the coarse part of the cyclic shift. In addition, a forward routing circular-shift (FRCS) network, which is based on the barrel shifter and the forward routing process is presented. The proposed switch network is able to support all 51 different submatrix sizes as defined in the 5G NR standard through an efficient forward routing switch network and help reduce the hardware complexity using a cyclic shift size decomposition method. The proposed MCSN is analyzed, and indicates a substantial reduction in the hardware complexity. The experimental results on TSMC 65-nm CMOS technology show that the proposed MCSN structure for 5G NR LDPC decoder offers an area saving up to 56.75% compared to related works in the literature.

Full-duplex transmission of multi-Gb/s subcarrier multiplexing and 5G NR signals in 39 GHz band over fiber and space

We propose a stable full-duplex transmission of millimeter-wave signals over a hybrid single-mode fiber (SMF) and free-space optics (FSO) link for the fifth-generation (5G) radio access networks to accelerate the Industry 4.0 transformation. For the downlink (DL), we transmit 39 GHz subcarrier multiplexing (SCM) signals using variable quadrature amplitude modulation (QAM) allocations for multi-user services. As a proof of operation, we experimentally demonstrate the transmission of 3 Gb/s SCM signals (1 Gb/s per user) over a hybrid system consisting of a 10 km SMF and 1.2 m FSO link. For the uplink (UL), satisfactory performance for the transmission of 2.4 Gb/s 5G new radio (NR) signal at 37 GHz over the hybrid system is experimentally confirmed for the first time, to the best of our knowledge. The measured error vector magnitudes for both DL and UL signals using 4/16/64-QAM formats are well below the third generation partnership project (3GPP) requirements. We also further evaluate by simulation the full-duplex transmission over the system in terms of received optical and RF powers and bit error rate performance. A wireless radio distance of approximately 200 m, which is sufficient for 5G small-cell networks, is estimated for both DL and UL direction under the heavy rain condition, based on the available data from Spain. Furthermore, simulation for the DL direction is conducted to verify the superior performance of the system using variable QAM allocation over uniform QAM allocation. Using a variable modulation allocation, up to five users (2 Gb/s per user) can be transmitted over a hybrid 10 km SMF and 150 m FSO link.

Practical Demonstration of 5G NR Transport Over-Fiber System with Convolutional Neural Network

This study describes an experimental realization using digital predistortion (DPD) for a fifth generation (5G) multiband new radio (NR) optical front haul (OFH) based Radio over Fiber (RoF) link. For the performance enhancement and complexity reduction of RoF links, a novel Convolutional Neural Network (CNN) based DPD technique is proposed, followed by comparisons with the generalised memory polynomial (GMP) based DPD method. To support enhanced mobile broad band scenario, the experimental testbed uses the 5G NR waveforms at 10 GHz with 20 MHz bandwidth and a flexible-waveform signal at 3 GHz with 20 MHz bandwidth. For 10 km of typical single mode fiber, a Mach Zehnder Modulator with two distinct radio frequency waveforms modulates a 1310 nm optical carrier utilizing distributed feedback laser. The error vector magnitude and number of estimated coefficients, and multiplications are all used to describe the experimental outcomes. The goal of the research is to see if CNN-based DPD improves performance while lowering complexity levels to meet 3GPP Release 17 criteria.

Enhancing5Gmulti‐bandlong haul optical fronthaul links performance by magnitude‐selective affine digital predistortion method

AbstractThis paper presents a novel magnitude‐selective affine (MSA) based digital predistortion (DPD) method for the performance investigation of multiband 5G new radio (NR) based analog radio over fiber link. The proposed MSA‐DPD method is derived from the canonical piecewise linear (CPWL) based model by employing MSA functions, which can result in reduction of the number of multiplication operations and the model complexity. The 5G NR standard at 20 GHz with 50 MHz bandwidth and flexible‐waveform signal at 3 GHz with 20 MHz bandwidth is used. A dual drive Mach Zehnder modulator having two distinct RF signals modulates a 1310 nm optical carrier using distributed feedback laser for 22 km of standard single mode fiber. The proposed MSA‐DPD method is compared with the CPWL and generalized memory polynomial method. The experimental results are presented in terms of adjacent channel power ratio, error vector magnitude, number of estimated coefficients and multiplications suggesting that MSA‐DPD method achieves a better performance as compared to CPWL and GMP models with much lesser complexity meeting the 3GPP Release 17 requirements.

Specification of downlink-fixed reference channel DL-FRC for 5G new radio technology

&lt;p&gt;The next generation for mobile communication is new radio (NR) that supporting air interface which referred to the fifth generation or 5G. Long term evolution (LTE), universal mobile telecommunications system (UMTS), and global system for mobile communication (GSM) are 5G NR predecessors, also referred to as fourth generation (4G), third generation (3G) and second generation (2G) technologies. Pseudo-noise (PN) code length and modulation technique used in the 5G technology affect the output spectrum and the payload of DL-FRC specification, in this paper quadrature phase shift keying (QPSK), 16 QAM modulation approaches tested under additive white Gaussian noise (AWGN) in term of bit error rate (BER) which used with 5G technology system implemented with MATLAB-Simulink and programing and, resulting of 1672, 12296 bit/slot payload at frequency range FR1 from 450 MHz-6 GHz and 4424, 20496 bit/slot payload at frequency range FR2 from 24.25 GHz-52.6 GHz, also determining subcarrier spacing, allocated source block, duplex mode, payload bit/slot, RBW (KHz), sampling rate (MHz), the gain and the bandwidth of main, side loop where illustrated.&lt;/p&gt;

Characterizing throughput and convergence time in dynamic multi-connectivity 5G deployments

Fifth-generation (5G) mobile communications are expected to integrate multiple radio access technologies (RATs) within a unified access network by allowing the user equipment (UE) to utilize them concurrently. As a consequence, mobile users face even more heterogeneous connectivity options, which creates challenges for efficient decision-making when selecting a network dynamically. In this work, with the tools of queuing theory, integral geometry, and optimization theory, we develop a novel mobility-centric analytical methodology for multi-RAT deployments. Particularly, we first contribute a framework for optimal data rate allocation in the network-assisted regime. Then, we characterize the convergence time of the distributed optimization algorithms based on reinforcement learning to reduce the signaling overheads. Our findings suggest that network-assisted strategies may improve the UE throughput by up to 60% depending on the considered deployment, where the gains increase with a higher density of millimeter-wave New Radio (NR) base stations. A user-centric solution based on reinforcement learning mechanisms is capable of approaching the performance of the network-assisted scheme. However, the associated convergence time may be prohibitive, on the order of several minutes. To improve the latter, we further propose and evaluate a transfer learning-based algorithm that allows to decrease the convergence time by up to 10 times, thus becoming a simple solution for rate-optimized operation in future 5G NR deployments.

Generation and Analysis of 5G Downlink Signal

The evolution of wireless communication technology has provided a viable important concept for the next-generation wireless mechanism. The Technology may provide a variety of services for different terminals, such as voice and multimedia data services through a mobile phone, as well as improved packet delivery across cellular networks. Fifth Generation (5G) New Radio (NR) is the most recent radio air interface designed for next-generation wireless communication networks to fulfill the increasing needs of connected devices. It is built to enable a variety of situations, including increased large machine-to-machine communications, mobile broadband, and ultra-reliable low-latency communications. The 5G NR signal is generated and analyzed using the various parameters in the waveform generator app in MATLAB. The downlink scenario is considered. The modulation used here for the generation of 5G signal is 16 QAM and 64 QAM modulation technique.

Cognitive Opportunistic Navigation in Private Networks With 5G Signals and Beyond

A receiver architecture is proposed to cognitively extract navigation observables from fifth generation (5G) new radio (NR) signals of opportunity. Unlike conventional opportunistic receivers which require knowledge of the signal structure, particularly the reference signals (RSs), the proposed cognitive opportunistic navigation (CON) receiver requires knowledge of only the frame duration and carrier frequency of the signal. In 5G NR, some of these RSs are only transmitted on demand, which limits the existing opportunistic navigation frameworks to signals which are on <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">always-on</i> ; hence, limiting the exploitable RS bandwidth. To exploit the full available bandwidth and improve ranging accuracy, the proposed CON receiver is designed to estimate all the RSs contained in the transmitted signals corresponding to multiple 5G base stations, (i.e., gNBs). Navigation observables (pseudorange and carrier phase) are subsequently derived from the estimated RSs. The proposed receiver operates in two stages: (i) acquisition and (ii) tracking. The acquisition stage of the CON receiver is modeled as a sequential detection problem where the number of gNBs and their corresponding RSs and Doppler frequencies are unknown. The generalized likelihood ratio (GLR) test for sequentially detecting active gNBs is derived and used to estimate the number of gNBs and their RSs. In order for the receiver to refine and maintain the Doppler and RS estimates provided by the acquisition stage, tracking loops are designed. A sufficient condition on the Doppler estimation error to ensure that the proposed GLR asymptotically achieves a constant false alarm rate (CFAR) is derived. The output of the tracking loops, namely carrier phase and code phase, are then used to estimate the receiver’s position. Extensive experimental results are presented demonstrating the capabilities of the proposed CON receiver with real 5G signals on ground and aerial platforms, with an experiment showing the first navigation results with real 5G signals on an unmanned aerial vehicle (UAV) navigating using the CON receiver over a 416 m trajectory with a position root mean-squared error (RMSE) of 4.35 m.

The 5G Cellular Downlink V2X Implementation Using V2N With Spatial Modulation

Fifth generation (5G) New Radio (NR) technology provides cellular vehicle-to-everything (C-V2X) communication. The 5G NR will utilize the existing uplink (UL) and downlink (DL) to furnish vehicle-to-network (V2N) communication via the cellular network. The new technology provides the enhanced throughput, edgeless connectivity, high reliability and the reduced latency for 5G DL V2X. With significantly reduced latency of NR, this paper shows that C-V2X can be implemented via 5G V2N communication. Spatial modulation is a good candidate to support unicast and groupcast for V2X services. We also discuss keyless security of 5G NR using physical layer security. The security of 5G NR can be implemented employing spatial modulation (SM) for unicast and groupcast in millimeter-wave (mmWave) communications with multiple-input and multiple-output (MIMO) channels.

Handover Solutions for 5G Low-Earth Orbit Satellite Networks

Low-Earth orbit (LEO) satellite networks are meant to be fundamental to closing the digital divide, enabling new market opportunities and providing fifth-generation (5G) New Radio (NR) connectivity everywhere at any time. Despite the advantages of LEO deployments, these systems are characterized by a high mobility and a challenging propagation channel that compromise several procedures of the current 5G standards. One of the impacted areas is the radio mobility management, which is used to ensure continuous and satisfactory service while users handover among cells. Current research shows that the measurement-based 5G NR handover (HO) procedures, designed for terrestrial networks, fail to ensure optimal mobility performance. In this work, we provide a mobility performance analysis through extensive system-level simulations of state-of-the-art HO procedures for 5G NR over LEO satellite networks with Earth-moving cells. Furthermore, this article presents a novel antenna gain-based HO solution for intra-satellite mobility that exploits the predictability of the satellites movement and the antenna gain of the satellite beams, making user equipment (UE)’s radio measurements obsolete. The system-level simulation results, which consider users in rural and urban scenarios, show that by exploiting the known satellite’s trajectory, the UE eliminates service failures and undesired HO events, maximises the time-of-stay in a cell and experiences improved downlink signal-to-interference-plus-noise ratio. This article also includes a sensitivity study of the impact on the mobility performance of satellite-specific and UE-specific errors such as the UE’s location error, the satellite beam’s antenna radiation error and the satellite’s pointing error. Finally, the impact of the UE’s mobility is analyzed.

Authentication and Handover Challenges and Methods for Drone Swarms

Drones are begin used for various purposes such as border security, surveillance, cargo delivery, visual shows and it is not possible to overcome such intensive tasks with a single drone. In order to expedite performing such tasks, drone swarms are employed. The number of drones in a swarm can be high depending on the assigned duty. The current solution to authenticate a single drone using a 5G new radio (NR) network requires the execution of two steps. The first step covers the authentication between a drone and the 5G core network, and the second step is the authentication between the drone and the drone control station. It is not feasible to authenticate each drone in a swarm with the current solution without causing a significant latency. Authentication keys between a base station (BS) and a user equipment (UE) must be shared with the new BS while performing handover. The drone swarms are heavily mobile and require several handovers from BS to a new BS. Sharing authentication keys for each drone as explained in 5G NR is not scalable for the drone swarms. Also, the drones can be used as a UE or a radio access node on board unmanned aerial vehicle (UxNB). A UxNB may provide service to a drone swarm in a rural area or emergency. The number of handovers may increase and the process of sharing authentication keys between UxNB to new UxNB may be vulnerable to eavesdropping due to the wireless connectivity. In this work, we present a method where the time and the number of the communication for the authentication of a new drone joining the swarm are less than 5G NR. In addition, group-based handover solutions for the scenarios in which the base stations are terrestrial or mobile are proposed to overcome the scalability and latency issues in the 5G NR.

Techno-Economic Assessment of 5G NSA Deployment for Metropolitan Area: A Greenfield Operator Scenario

Indonesia is the fourth-most populous country, with 260 million people. This increases telecom network demand. 4G-LTE is Indonesia's lea ding mobile technology (LTE), but its network is now crowded. The telecom business must adjust to consumer mobility and growing demand. The Indonesian government urges the deployment of 5G New Radio (NR) with Non-Stand Alone (NSA) model in 13 Indonesian cities area, especially in the capital city of Jakarta, which is the economic and government center of Indonesia. This research attempts to determine the technological and economic plans needed to satisfy the 5G NR mid-band 3.5 GHz with the NSA model for both capacity and coverage needs in a metropolitan and denseurban area of Indonesia, Jakarta City. This research utilized mid-band 3.5 GHz frequency due to its ability to hold optimum capacity and coverage, especially for greenfield operator scenarios (new mobile operators). According to analysis, all Jakarta municipals will need 919 5G NR 3.5 GHz gNodeB and create 17.7 Gbps/km2 of traffic. Synchronization Signal-Reference Signal Received Power (SS-RSRP) averages -93.27 dBm and is rated good, while SS-SINR averages 8.89 dB and is considered fair. In terms of economics, total CAPEX is IDR 147,184,134,855, total OPEX is IDR 1,004,463,403,900, Net Present Value (NPV) is IDR 477,532,953,385, Internal Rate of Return (IRR) is 24.7%, Payback Period (PBP) is 3.87 or within three years and ten months, and Profitability Index (PI) is 1.42. Meanwhile, the results of the sensitivity analysis indicates that the number of gNodeB and the number of users are the most significant parameters that greatly affect the business feasibility of deploying 5G NR NSA with 3.5 GHz in the metropolitan area of Jakarta City.

Joint Synchronization and Compressive Channel Estimation for Frequency-Selective Hybrid mmWave MIMO Systems

Synchronization is a fundamental procedure in cellular systems whereby user equipment (UE) acquires the time and frequency information required to decode the data transmitted by a base station (BS). Due to the small antenna aperture at millimeter wave (mmWave), large antenna arrays are used to compensate for the low signal-to-noise ratio (SNR) at the receiver. For this reason, synchronization is often performed jointly with beam training as in 5G New Radio (NR) to boost the receive SNR. However, if the mmWave multiple-input multiple-output (MIMO) channel is to be estimated, then synchronization must be performed in the low SNR regime owing to the lack of directional beamforming during compressive channel estimation. Current mmWave channel estimation algorithms implicitly take synchronization for granted, which is a not practical assumption in the low SNR regime. To solve this problem, this work proposes the first synchronization framework for hybrid mmWave MIMO that is robust to carrier frequency offset (CFO) and phase noise (PHN) synchronization errors. We propose two novel multi-stage algorithms to jointly estimate the various unknown parameters, based on the expectation-maximization (EM) algorithm. By using the QuaDRiGa 5G NR channel simulator, we show that compressive channel estimation without prior synchronization is possible, and the proposed approaches outperform current solutions for joint beam training and synchronization currently considered in 5G NR.

Security of communication 5G-V2X: A proposed approach based on securing 5G-V2X based on Blockchain

With the rapid evolution of wireless communication and autonomous vehicles, vehicle to Everything (V2X) communications provides driving safety, traffic efficiency, and real-time traffic information in-vehicle networks. V2X has evolved by integrating 5G cellular access technology and New Radio (NR) into V2X communications (i.e., 5G NR V2X). Since the security issue in 5G-V2X remains a crucial point, we conducted a literature review approach and identified the 5G-V2X communication levels in this paper. The main objective of this study was to develop an approach to secure 5G-V2X. The proposed methodology is based on Blockchain to ensure the 5G-V2X architecture levels.

High-Performance and Low-Complexity Decoding Algorithms for 5G Low-Density Parity-Check Codes

The development of the Fifth Generation (5G) New Radio (NR) provides several significant advantages when compared to the fourth generation (4G) Long Term Evolution (LTE) in mobile communications. Due to the outstanding characteristics of Low-Density Parity-Check (LDPC) codes such as high decoding performance, high throughput, low complexity, they have been accepted as the standard codes for the 5G NR. In this paper, we propose two LDPC decoding algorithms: Hybrid Offset Min-Sum (HOMS) and Variable Offset Min-Sum (VOMS), which are aimed at improving the error correction performance. The main idea of the HOMS/VOMS algorithm is to apply modified factors to both variable-nodes and check-nodes updated processing in order to compensate the extrinsic messages overestimation of the MS-based algorithms and increase the protection ability for degree-1 variable-nodes. The simulation results show that at the Bit-Error-Rate (BER) of 10-5, the proposed HOMS/VOMS algorithm achieves the decoding gain up to 0.2 dB compared to the Offset Min-Sum (OMS) algorithm, with a slight increase in decoding complexity.

FPGA Implementation of 5G NR Primary and Secondary Synchronization

The 5G communication systems are widely established for high-speed data processing to meet users demands. The 5G New Radio (NR) communications comprise a network of ultra-low latency, high processing speeds, high throughput and rapid synchronization with a time frame of 10 ms. Synchronization between User Equipment (UE) and 5G base station known as gNB is a fundamental procedure in a cellular system and it is performed by a synchronization signal. In 5G NR system, Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS) are used to detect the best serving base station with the help of a cell search procedure. The paper aims to determine the Physical Cell Identity (PCI) by using primary synchronization and secondary synchronization blocks. The PSS and SSS detection for finding PCI is implemented on Zynq-7000 series Field Programmable Gate Arrays (FPGA) board. FPGA are reconfigurable devices and easy to design complex circuits at high frequencies. The proposed architecture employs Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS) detection aims with high speed and low power consumption. The synchronization blocks have been designed and the synthesized design block is implemented on the Zynq-7000 series Zed board with a maximum operating clock frequency of 1 GHz.

High gain of 28 GHz transparent antenna for 5G NR Networks

A new compact transparent patch antenna for 5G new radio (NR) is presented in this paper. Small rectangles are cut out from the patch to produce the desired frequency 28 GHz. The AgHT-8 material is used to from the radiator and the ground of the antenna while the glass is used as a substrate with a relative permittivity of εr = 4.6, tanδ = 0.0036 and thickness of 1.1mm. The suggested antenna occupies a small footprint of only 104,72 mm2 (11mm x 9.52 mm). The frequency bandwidth operation of the antenna is 3.624GHz (26.369 - 29.993 GHz) centered at 28GHz, the efficiency is 76% and the gain is about 5.1 dBi. The excellent performance allows the transparent antenna suitable for 5G applications.

5G NR Configured Grant in ns-3 Network Simulator for Ultra-Reliable Low Latency Communications

5th Generation (5G) and Beyond networks are being designed to support Ultra-Reliable and Low Latency Communications (URLLC). To this end, 5G defines a new radio (NR) interface with a new mechanism at the Physical (PHY) and Medium Access Control (MAC) layers that allow reducing the latency communication. One key mechanism to reduce the latency is the scheduling scheme. Mainly, 5G defines the use of the configured grant (CG) scheduling for uplink (UL) transmissions that eliminates the need to request and assign resources for each packet transmission by pre-allocating resources to the UE. The availability of simulation tools that accurately model the new mechanisms and technologies incorporated in 5G New Radio (NR) is key to research and evaluate new proposals and enhancements to meet the communication requirements of emerging services. In this context, this paper presents the implementation of the configured grant scheduling in the ns-3 network simulator. Remarkably, the configured grant has been implemented within the 5G-LTE-EPC Network simulAtor (5G-LENA) module that simulates the fundamental PHY-MAC NR features in line with the NR specifications. In addition, this paper validates the configured grant implementation through system-level simulations considering a typical Industry 4.0 scenario characterized by applications demanding URLLC.