Throughput Analysis over 5G NR Physical Uplink Shared Channels

In fifth-generation (5G) new radio (NR) integrated sensing and communication (ISAC) systems, the overhead of sensing time resources in waveform design is a key metric. Traditional uniform pulse sensing waveforms, which require fixed time slot positions, incur large sensing overhead and may not be feasible within the context of existing 5G NR standards for low-latency scenarios. To address this issue, two novel frame-level sensing waveform designs based on double coprime sampling are proposed via downlink sensing. Specifically, two types of novel orthogonal frequency-division multiplexing (OFDM) structure pulse sensing waveforms based on coprime sampling are first proposed to accommodate the specific 5G NR frame structure. Then, a low-complexity frequency-domain radar signal processing method is proposed for sensing target detection and velocity estimation based on the constructed equivalent virtual fast-slow-time domain signal. Moreover, the theoretical sensing performance of the proposed waveforms and the computational complexity of the sensing method are thoroughly analyzed. Compared with the conventional uniform OFDM-based waveform design, the proposed coprime-based frame-level OFDM sensing waveforms utilize significantly fewer time slots, resulting in reduced sensing overhead with slight sensing performance loss. Numerical examples are presented to illustrate that the proposed waveforms can offer robust sensing performance with reduced sensing overhead and have a computational complexity a little higher than that of conventional fast Fourier transform algorithms.

A two-way fifth-generation (5G) new radio (NR) free-space optical (FSO)-hollow-core fibre (HCF)-underwater wireless optical communication (UWOC) converged systems with a red/green/blue (R/G/B) 3-wavelengths and spatial light modulator (SLM)-based beam-tracking scheme is practically built. It is the first to practically build a two-way FSO-HCF-UWOC converged system with high-speed and long-distance optical wireless-wired-underwater wireless communication characteristics. It shows a 5G NR FSO-HCF-UWOC convergence from drone or buildings to undersea, using R/G/B 3-wavelengths and an SLM as a demonstration. The R/G/B 3-wavelengths are used to enhance the downstream and upstream aggregate transmission rates. An SLM with electrical comparator is used to adjust the laser beam and mitigate laser beam misalignment caused by drone movement or ocean flow. Over a hybrid of 1-km FSO, 10-m HCF, and 10.44-m ocean water-air-ocean water medium, downstream/upstream 5G-millimeter-wave (MMW) 9.1-Gb/s/24-GHz signals are transmitted with satisfactorily low bit error rates and error vector magnitudes, as well as distinct constellations. This demonstrated that the 5G NR FSO-HCF-UWOC converged system exhibits promising potential as it advances the scenario implemented by the 5G-MMW signals over FSO, HCF, and UWOC convergence, paving the way for high-speed and long-distance communications across diverse media.

With the speeding up of the fifth generation (5G) new radio (NR) worldwide commercialization, one of the paramount questions for operators and vendors is how to optimize the radio links, considering the widely diverse scenarios envisioned. One of the key pillars of 5G has been an unprecedented flexibility on the configuration of the radio access network (RAN) on scenarios that include cellular, vehicular, and industrial networks among others. This flexibility has its main exponent on link adaptation (LA), which has evolved into a <italic>multi-domain</italic> technique where a plethora of parameters, like numerology, bandwidth part, radio frequency beam, power, modulation and coding scheme (MCS) or multiple antenna precoding can be adapted to the instantaneous link conditions. Although such enhancements open the door to a significant performance improvement, they also pose many challenges to LA optimization. In this article, we first present the signaling aspects of NR technology for multi-domain LA and the challenges that need to be faced. Then, we explore the latest advances on LA for wireless networks. We envision a combination of machine learning (ML) tools with multi-domain LA as a key enabler for 5G and beyond networks. Finally, we investigate emerging ML approaches for LA and present a promising application of ML for LA that is assessed with simulations. With this scheme, the training is performed at the network side to relieve the user equipment (UE) to do such a complex task. It is shown with simulations that our ML approach outperforms the well-known outer loop link adaptation (OLLA) algorithm in terms of instantaneous block error rate (BLER), while reaching the same average spectral efficiency (SE). Interestingly, it is shown that the proposed scheme only requires 4 bits to represent the features used to train the model, which makes it suitable for implementation in real systems with limited feedback.

In fifth generation (5G) new radio (NR), the medium access control (MAC) layer organizes the data into the transport block and transmits it to the physical layer. The transport block consists of up to million bits. When the transport block size exceeds a threshold, the transport block is divided into multiple equal size code blocks. The code block consists of up to 8448 bits. Both the transport block and the code block have a cyclic redundancy check (CRC) attached. Due to the difference in the size of the transport block and the code block, the CRC processing scheme suitable for the transport block and that suitable for the code block are different. This chapter gives an overview of the CRC implementation in 5G NR.

This work reports the implementation of a fifth‐generation (5G) new radio (NR) fiber‐wireless (FiWi) system for long‐reach and enhanced mobile broadband scenarios. The proposed 5G NR FiWi system includes a 12.5 km optical distribution network based on radio over fiber technology, a 7.5 km supercell in a rural area using the 700 MHz band, digital pre‐distortion (DPD), equalization and a Gbit/s indoor femtocell operating in the 26 GHz band. The 5G NR standard has been applied and DPD and equalization have been efficiently employed to enhance the system performance in mm‐waves. Furthermore, experimental results demonstrate successful implementations of a femtocell with 4 Gbit/s throughput and only 4.6% error vector magnitude, as well as a large cell with 33 Mbit/s throughput and 7.51‐km reach.

Fifth-generation (5G) networks are evolving from special purpose-built networks to software-defined, intelligent, multipurpose networks, enabling service innovation and autonomous network operation. In this article, we present an intelligent mobile edge network based on standardized 5G network function entities and New Radio (NR) radio access networks (RANs). We propose a multitier, self-organizing network (SON) with a middle-tier SON (mSON), centralized SON (cSON), and distributed SON (dSON) to support increasing network dynamicity for different verticals and to take advantage of the latest high-layer F1 interface. This is essential to support low-latency applications and ultrahigh-reliability services. It also enables more dynamically tight interworking of 5G NR and LTE with dual connectivity, expanding initial 5G NR coverage. We analyze a lower-layer RAN split to optimize fronthaul and so further improve radio efficiency by utilizing the multitier SON among various radio nodes as well as distributed units (DUs) and centralized units (CUs). This will facilitate massive multiple-input/multiple-output (MIMO) antenna systems and accelerate centralized and virtualized RAN deployments.

This paper describes and investigates a novel concept of frequency-domain spectral shaping (FDSS) with spectral extension for the uplink (UL) coverage enhancement in 5G New Radio (NR), building on discrete Fourier transform spread orthogonal frequency-domain multiplexing (DFT-s-OFDM). The considered FDSS concept is shown to have large potential for reducing the peak-to-average-power ratio (PAPR) of the signal, which directly impacts the feasible maximum transmit power under practical nonlinear power amplifiers (PAs) while still meeting the radio frequency (RF) emission requirements imposed by the regulations. To this end, the FDSS scheme with spectral extension is formulated, defining filter windows that fit to the 5G NR spectral flatness requirements. The PAPR reduction capabilities and the corresponding maximum achievable transmit powers are evaluated for a variety of bandwidth allocations in the supported 5G NR frequency ranges 1 and 2 (FR1 and FR2) and compared to those of the currently supported waveforms in 5G NR, particularly <inline-formula> <tex-math notation="LaTeX">$\pi /2$ </tex-math></inline-formula>-BPSK with FDSS without spectral extension and QPSK without FDSS. Furthermore, an efficient receiver structure capable of reducing the noise enhancement in the equalization phase is proposed. Finally, by evaluating the link-level performance, together with the transmit power gain, the overall coverage enhancement gains of the method are analyzed and provided. The obtained results show that the spectrally-extended FDSS method is a very efficient solution to improve the 5G NR UL coverage clearly outperforming the state-of-the-art, while being also simple in terms of computational complexity such that the method is implementation feasible in practical 5G NR terminals.

5G new radio (NR) introduced flexible numerology to provide the necessary flexibility for multiplexing the communication of heterogeneous services on a shared channel. One of the fundamental challenges of 5G NR is to develop resource allocation schemes to efficiently exploit such flexibility to optimize resource allocation of ultra-reliable low-latency communications (URLLC) in coexistence with enhanced mobile broadband (eMBB) while ensuring their colliding performance requirements. This problem of 5G NR resource allocation to URLLC services coexisted with eMMB services is an NP -hard problem. We present a new formulation of this problem by considering the interplay of eMBB and URLLC services’ constraints and targets. The objective of the formulated problem is to probabilistically meet quality of service (QoS) requirements of both eMBB and URLLC services when the optimal global solution is infeasible. To this end, we express the problem as an integer linear programming problem and consider two formulations with hard and soft URLLC throughput constraints. The overall problem is then treated as a specific instance of bin packing optimization, whose objective is to minimize the placements of URLLC services. We apply a greedy resource allocation algorithm to provide a near-optimal solution in polynomial-time to this problem. Finally, we numerically evaluate the optimal solutions of the two different formulations. Performance results demonstrate and confirm that the proposed 5G NR resource allocation solutions can provide efficient resource utilization while satisfying the performance requirements of the eMBB and URLLC services.

Environmental sensing is a pivotal technology that utilizes sensor data to enable vehicles, robots, and drones to accurately perceive their surroundings. The emergence of 5G New Radio (NR) networks as specialized sensors for environmental sensing has become a promising research direction, particularly within the context of integrated sensing and communication (ISAC) systems. One category of ISAC research in 5G NR primarily focus on radar signal modeling to create range-Doppler imaging maps. However, the generation of range-Doppler maps demands a significant amount of continuous data in the time-frequency domain, which is usually unavailable in localization tasks that rely on time domain data. This paper focuses on utilizing the downlink pilots in 5G NR without modifying the existing communication functions, aiming to propose an implementation algorithm for sensing from the perspective of the channel model. Firstly, we investigate the performance of an inverse discrete Fourier transform (IDFT)-based channel impulse response (CIR) ranging scheme. Secondly, a CIR-based back projection (BP) algorithm for sensing is proposed, which exploits the downlink pilots of 5G NR. In this algorithm, the transceiver pair consisting of a gNB and user equipment (UE) is treated as a subaperture, and the subapertures from all gNBs are combined to emulate the effect of a synthetic aperture. Finally, the performance of the CIR-based BP sensing algorithm is demonstrated through simulations. Notably, the advantage of the proposed method is that it does not require redesigning 5G NR signals, does not interfere with communication functions, and only requires the pilot from a single orthogonal frequency division multiplexing (OFDM) symbol for sensing, thereby offering an innovative approach to environmental sensing and localization.

The recently developed fifth generation (5G) of mobile communication has several advanced features. It would be very much different from the previous versions of the mobile generations in several aspects. Based on the performance, 5G will have gigantic data rates, very low end-to-end latency, high spectral efficiency, very high device densities, high energy efficiency, and seamless connectivity with devices and sensors. These advanced features will bring several differences in the 5G architecture. The differences will be both in the core, and access parts of these new networks. While the core will be comprised of high speed optical fibers, the access will have advanced wireless technologies such as massive MIMO, beamforming, energy efficient waveforms, new radio access technologies, and new full duplex channels. In this article, we present the new features and their performance characteristics of 5G access networks. We show the newly proposed standards in place for the 5G new radio (NR). The 5G NR is going to frame the practical aspects of 5G in the wireless form. Based on the 5G NR, the access networks of 5G will have several new initiatives such as new spectrum for communication, too many small cells, massive MIMO antennas, exploiting the space diversities, and advanced signal processing techniques to deal with these complexities. Finally, at the user’s end, a high data rate is delivered with very low latency.

This paper considers the uplink of a single-cell large-scale multiuser multiple-input multiple-output (MU-MIMO) system. The transmitted data is detected by linear receivers at the base station (BS), that is, maximum ratio combining (MRC), zero-forcing (ZF) and minimum mean square error (MMSE). New non-asymptotic outage expressions that are valid for any number of BS antennas are derived. It is shown that the MMSE scheme always achieves the best outage performance, and the ZF scheme outperforms the MRC scheme in the high signal-to-noise-ratio (SNR) regime, while the opposite holds in the low SNR regime. We also demonstrate that when the number of BS antennas is very large and the number of users is fixed, the asymptotic outage probability tends to zero, providing that the channel state information (CSI) is perfect. However, if both the number of BS antennas and the number of users grow large, it would be a different matter. Extensive numerical results are presented to verify the theoretical analysis.

ETSI DECT-2020 New Radio (NR) is a new flexible radio interface targeted to support a broad range of wireless Internet of Things (IoT) applications. It has been shown to fulfill both massive machine-type communications (mMTC) and ultra-reliable low latency communications (URLLC) requirements for 5th generation (5G) networks. DECT-2020 NR is an autonomous wireless mesh network protocol where the devices can choose to become routers, forwarding the data of other devices in addition to their own data. Thus, a wireless mesh network does not need separate base stations or a core network architecture to extend coverage. This makes the deployment of DECT-2020 NR networks easy, but with the cost of increased energy consumption in the router nodes. Notably, the same energy consumption is not inflicted upon the non-routing leaf nodes whose operation is on the contrary very energy efficient. This role-induced disparity in node energy consumption results in the network not using the energy of its devices with maximal efficiency. A method to alleviate this problem could be a network rotation in which the roles of network nodes are periodically rotated and the energy consumption is thus distributed more evenly among the nodes. In this paper we propose a role rotation protocol for DECT-2020 NR and evaluate its impact to the expected lifetime and the performance of the network by system level simulations.

STARE, a real-time SofTwAre REceiver for positioning with the long-term evolution (LTE) and fifth-generation (5G) new radio (NR) cellular downlink signals, is presented and demonstrated. The real-time operation is achieved by interfacing directly with the software-defined radio (SDR), therefore avoiding the requirement to store the captured signal on a drive and allowing to process signals continuously over arbitrarily long periods. STARE supports multi-channel SDRs and parallel execution of an arbitrary number of tracking channels, which independently acquire and track the desired signals. During the acquisition stage, the tracking channel applies a path selection criterion based on the signal-to-noise ratio (SNR) of the earliest path to prevent incorrect delay and phase estimation, which may occur when the channel order is overestimated. The design of the tracking stage follows a closed-loop architecture providing a continuous estimation of the delay, Doppler, phase, and SNR. The real-time operation of STARE is demonstrated by monitoring downlink signals of a commercially operated LTE base station for an uninterrupted period of one week. For this purpose, STARE is deployed on a static monitoring setup composed of a processing unit, an SDR, an omnidirectional antenna, and a high-precision Rubidium reference clock. The collected measurements are used to study the SNR and delay errors. The delay errors are estimated using the code-minus-carrier (CMC) technique and are observed to achieve a sub-meter standard deviation.

Recently, the Third Generation Partnership Project (3GPP) introduced new radio (NR) technology for vehicle-to-everything (V2X) communication to enable delay-sensitive and bandwidth-hungry applications in vehicular communication. The NR system is strategically crafted to complement the existing long-term evolution (LTE) cellular-vehicle-to-everything (C-V2X) infrastructure, particularly to support advanced services such as the operation of automated vehicles. It is widely anticipated that the fifth-generation (5G) NR system will surpass LTE C-V2X in terms of achieving superior performance in scenarios characterized by high throughput, low latency, and enhanced reliability, especially in the context of congested traffic conditions and a diverse range of vehicular applications. This article will provide a comprehensive literature review on vehicular communications from dedicated short-range communication (DSRC) to NR V2X. Subsequently, it delves into a detailed examination of the challenges and opportunities inherent in NR V2X technology. Finally, we proceed to elucidate the process of creating and analyzing an open-source 5G NR V2X module in network simulation-3 (ns-3) and then demonstrate the NR V2X performance in terms of different key performance indicators implemented through diverse operational scenarios.

Interleaver module is an important part of modern mobile communication system. It plays an important role in reducing bit error rate and improving transmission efficiency over fading channels. In 5G NR (5th Generation New Radio) standards, LDPC (low-density parity-check) and polar channel codes are employed for data channels and control channels, respectively. If multiple interleavers are implemented separately for them, the cost increases significantly. To address this issue, a hardware multiplexing scheme for channel interleavers based on LDPC and polar codes is proposed in this paper. Firstly, the formulas for the processes of the control channel interleaving and data channel interleaving are derived with respect to 5G NR standard. Then, the hardware implementation structures of the two interleavers are given. Subsequently, hardware reuse is proposed by sharing the similar or identical parts between the two hardware structures. Simulation results verify the correctness of our proposed scheme and demonstrate that it can realize the hardware sharing of the two kinds of channel interleavers to reduce the cost of silicon.