Radio Interface Technologies Research Articles

Path Loss Characterization in an Outdoor Corridor Environment for IoT-5G in a Smart Campus University at 850 MHz and 3.5 GHz Frequency Bands.

The usage scenarios defined in the ITU-M2150-1 recommendation for IMT-2020 systems, including enhanced Mobile Broadband (eMBB), Ultra-reliable Low-latency Communication (URLLC), and massive Machine Type Communication (mMTC), allow the possibility of accessing different services through the set of Radio Interface Technologies (RITs), Long-term Evolution (LTE), and New Radio (NR), which are components of RIT. The potential of the low and medium frequency bands allocated by the Federal Communications Commission (FCC) for the fifth generation of mobile communications (5G) is described. In addition, in the Internet of Things (IoT) applications that will be covered by the case of use of the mMTC are framed. In this sense, a propagation channel measurement campaign was carried out at 850 MHz and 5.9 GHz in a covered corridor environment, located in an open space within the facilities of the Pedagogical and Technological University of Colombia campus. The measurements were carried out in the time domain using a channel sounder based on a Universal Software Radio Peripheral (USRP) to obtain the received signal power levels over a range of separation distances between the transmitter and receiver from 2.00 m to 67.5 m. Then, a link budget was proposed to describe the path loss behavior as a function of these distances to obtain the parameters for the close-in free space reference distance (CI) and the floating intercept (FI) path loss prediction models. These parameters were estimated from the measurements made using the Minimum Mean Square Error (MMSE) approach. The estimated path loss exponent (PLE) values for both the CI and FI path loss models at 850 MHz and 3.5 GHz are in the range of 2.21 to 2.41, respectively. This shows that the multipath effect causes a lack of constructive interference to the received power signal for this type of outdoor corridor scenario. These results can be used in simulation tools to evaluate the path loss behavior and optimize the deployment of device and sensor network infrastructure to enable 5G-IoT connectivity in smart university campus scenarios.

Comparison of different New Radio (NR) waveforms for wireless communications.

New Radio (NR) waveforms of existing wireless communication systems need further improvement in order to support future wireless communications. NR is the radio interface technology proposed by the 3rd Generation Partnership Project (3GPP) for 5G. Prototype Filter (PF) of NR plays a vital role in performance improvement of wireless systems. NR waveforms can adapt in a better way to different channel conditions. Some of the NR filtering techniques are Filtered-OFDM (F-OFDM), Filter Bank Multi-Carrier (FBMC), and Universal Filtered Multi-Carrier (UFMC). NR waveforms require performance improvement when high reliability, massive connectivity, lower power consumption, and time-critical applications are required. Areas of improvement are Power Spectral Density (PSD), Bit Error Rate (BER), Signal to Interference Ratio (SIR), Doppler Diversity, and Peak to Average Power Ratio (PAPR). This paper compares different performance parameters of Filtered-OFDM, FBMC, and UFMC using existing proto-type filters and novel proto-type filters. The novel and better PFs, described in the paper, were proposed first time by the authors and his research group. Proposed novel prototype filters for FBMC, Filtered-OFDM, and UFMC are respectively Binomial filter and Fractional Powered Binomial Filter (FPBF). With FPBF based OFDM, PSD improvement was 97.5 dB, and BER improvement was 0.07 at 0 dB SNR. With Binomial filter based FBMC, OOBE improvement was 19.7 dB and BER improvement was 0.03 at 0 dB SNR. PAPR improvement with Binomial filter based FBMC was 1.16 dB at 64-QAM and 1.1 dB at 256-QAM. With FPBF based UFMC, improvement of interference level was 122 dB within 3rd~52th sub-bands due to 1st sub-band. BER improvement was 0.09 at 0 dB SNR. SIR improvement was 5. 27 dB with 15 KHz sub-carrier spacing and 16.55 dB with 30 KHz sub-carrier spacing of UFMC. Novel NR filters, discussed in the paper, are good candidates for future 6G wireless systems.

Impact of Inter Cell Interference on the Performance of Homogenous Cellular Systems

Deployment of cellular system with frequency reuse of one is critical to support increased data traffic and high data rate applications in 4G and beyond radio interface technologies. Such deployment leads to substantial increase in Inter-Cell Interference (ICI). Therefore, this paper investigates and evaluates the capacity performance of mobile cellular system with a frequency reuse of one and three-sector per Base Station (BS). The communication channel between the BSs and user equipment links is modeled using ITU-R channel model. The study considers different carrier frequencies and different cell ranges. The system performance is assessed in terms of Signal to Noise Ratio (SNR), Signal to Interference plus Noise Ratio (SINR) and ergodic capacity. The SNR and ergodic capacity improve significantly as the cell range and carrier frequency decreases for ICI free scenario. However, for ICI scenario, there are slight variation in the performance when changing the cell range and the carrier frequency. The study recommends a cell size of 800 m.

Cognitive Network Architecture Systems to Provide Intelligent Services: An Intelligent Self-Organization Approach With a Game-Based Incentive Mechanism

There will exist a growing interest in deploying data-intensive and content-rich applications on mobile smart devices. Also, ultrareliable and low-latency communications will be the critical requirements for obtaining good quality of experience for users of smart devices. However, the existing cellular architectures hardly provide a rich and stable spectrum supply to support ultrareliable and low-latency communications. Although future wireless networks are expected to effectively exploit the terahertz frequency band, it is difficult to obtain stable, ultrareliable, and low-latency communications due to the immaturity of both propagation models and radio interface technologies in such a high-frequency band. Therefore, this article introduces cognitive network brokers based on a data-driven cognitive network architecture to integrate and make full use of various resources to provide good network services for users, including an engine for spectrum and device cognition and an engine for cognitive network service construction.

Sub-terahertz propagation characteristics up to 150 GHz for 6G mobile communication systems

AbstractExtreme-high-speed communication exceeding 100 Gbps is one requirement for 6G. To satisfy extreme-high-speed-communication, one solution is to utilize terahertz bands above 100 GHz. To determine the new radio-interface technologies and service frequency bands for 6G, terahertz propagation characteristics above 100 GHz need to be understood. In this paper, we introduce our new radio-network topology for 6G and then show the frequency dependency of key propagation phenomena such as the characteristics of path loss in an urban environment, human blockage, and scattering from a rough building surface up to 150 GHz. Human blockage loss increases and the scattering is more diffused as the frequency increases. In the path-loss characteristics, it was found that path-loss frequency dependency is stronger than that given by conventional path-loss model because of scattering effects from a rough building surface.

5G New Radio Key Performance Indicators Evaluation for IMT-2020 Radio Interface Technology

The International Telecommunication Union (ITU) has recently announced the detailed 5G specifications for International Mobile Telecommunications (IMT-2020). A number of candidate Radio Interface Technologies (RITs) were being evaluated by the independent evaluation groups of the ITU. Meanwhile, the roll out of fifth generation (5G) is now going on, and 5G services are offered by more than 160 mobile network operators (MNO). This paper presents the evaluation of the proponent technologies, including the ones specified as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3^{\text {rd}}$ </tex-math></inline-formula> generation partnership project (3GPP) 5G new radio (NR). The entire 3GPP specifications were examined and evaluated through simulation using Matlab and a custom simulator based on the Go-language. The simulator facilitated the comprehensive evaluation of the 5G NR performance by using the IMT-2020 evaluation framework. Some of the submitted technologies displayed certain discrepancies which were reported to ITU as well as discussed with proponents to improvise the shortcomings. The detailed results and observations are presented in this paper.

Backhaul Aware User-Specific Cell Association Using Q-Learning

With the advent of network densification and the development of other radio interface technologies, the major bottleneck of future cellular networks is shifting from the radio access network to the backhaul. The future networks are expected to handle a wide range of applications and users with different requirements. In order to tackle the problem of downlink user-cell association, and allocate users to the best cell, an intelligent solution based on reinforcement learning is proposed. A distributed solution based on Q-Learning is developed in order to determine the best cell range extension offsets (CREOs) for each small cell (SC) and the best weights of each user requirement to efficiently allocate users to the most appropriate SC, based on both backhaul constraints and user demands. By optimizing both CREOs and user weights, a user-specific allocation can be achieved, resulting in a better overall quality of service. The results show that the proposed algorithm outperforms current solutions by achieving better user satisfaction, mitigating the total number of users in outage, and minimizing user dissatisfaction when satisfaction is not possible.

Path Loss with Doppler Shift Effect and Handover Delay Analysis on Cellular Communication for Connected Car Application in Urban Area

In this paper, the study on path loss and delay of cellular communication is conducted by considering doppler shift fading effect, shadowing effect and handover session in urban area. The experiment will consist observation on three different wireless communication module. This three-wireless module will have different carrier frequency and radio interface technologies to determine the effect of doppler shift to communication path loss and handover delay of a moving vehicle. The path loss of a moving vehicle will be determined based on measured received power on communication modules antenna and transmit power from base station. Handover delay that experienced by a moving vehicle will be measured based on data transmission latency during communication session transferring from previous cell network area that pass by the vehicle to a new cell network area. From this experiment, the best selection of wireless communication module by considering doppler shift effect and handover delay in urban area is determined as suited module to be use on connected car system.

Demonstrability of Narrowband Internet of Things technology in advanced metering infrastructure

The deployment cost of advanced metering infrastructure (AMI), one of the key elements for smart grid, often arises from three sub-systems, respectively referred to as data management system, communication network, and smart devices. Among them, the costs of communication network account for a considerable proportion. In smart grid, smart devices are generally fixed in a certain position and schedule reading of interval meter data. They do not only cover smart meters, but also extend gas, water meters, and other sensors measuring light, humidity, and temperature. Many of them are often with battery supply, and this will bring utilization constraints especially in communication network. The deployment needs of reducing cost and the energy-constrained network for an extremely large-scale AMI infrastructure both require optimum communication technologies that consider energy consumption, minimize energy use, simplify network topology, and prolong network lifetime. As an emerging 3GPP radio interface technology specifically designed for low power wide area networks (LPWANs), Narrowband Internet of Things (NB-IoT) inherits from the existing LTE but does many simplifications. Its most prominent features, enhanced coverage and low power consumption, are being pursued for a large-scale AMI communication network. In this paper, we provide a survey of AMI communication, emphasize on the key technologies of NB-IoT, analyze the performance of NB-IoT network over a real-world, and demonstrate the potential of NB-IoT to support and boost AMI in smart grid.

Analysis of 5G New Radio Uplink Signals on an Analogue-RoF System Based on DSP-Assisted Channel Aggregation

The 3rd Generation Partnership Project (3GPP) is in the process of developing 5th generation (5G) radio access technology, the so-called new radio (NR). The aim is to achieve the performance requirements forIMT-2020 radio interface technology. In this paper, we focus on the analysis of the transmission of 5G NR uplink physical channels, such as physical uplink shared channel (PUSCH) and physical uplink control channel (PUCCH), dedicated for data and control channels, respectively, as specified in the 3GPP standard, using digital signal processing (DSP)-assisted frequency division multiple access (FDMA) and time division multiple access (TDMA) channel aggregation techniques on an analogue radio-over-fiber (A-RoF) architecture. We verified that there is ~34% spectral efficiency gain and lower error vector magnitude (EVM) achieved using the TDMA technique.

LTE‐Advanced network inter‐cell interference analysis and mitigation using 3D analogue beamforming

This study considers the effects of inter-cell interference (ICI) on the LTE-Advanced physical layer downlink channel for different macro-cell diameters and base station (BS) antenna heights with a frequency reuse factor of one and three sectors per site. A site-specific three-dimensional (3D) ray-tracing tool is used to model the communication channel between the BSs (main and interfering links) and user equipment (UE) terminals. System performance is evaluated in terms of average spectrum efficiency, cell edge throughput and outage probability. Two 3D analogue beamforming algorithms are proposed to mitigate the harmful effects of ICI. These are applied at the BS and/or the UE and compared with a more traditional fractional frequency reuse deployment. Simulations demonstrate that the proposed beamforming algorithms provide significant system level improvements, especially for low BS antenna heights. With 10 × 10 and 2 × 2 antenna arrays at the BS and the UE, respectively, the proposed MaxMin-BF algorithms can provide an average spectrum efficiency of 3.6 bps/Hz and a cell edge throughput of 0.56 bps/Hz up to a cell diameter of 1250 m. Importantly, these results satisfy the IMT-Advanced requirements for candidate fourth generation and beyond radio interface technologies. Furthermore, the performance of proposed beamforming algorithms outperforms those achieved using fractional frequency reuse.

WiSE: A System-Level Simulator for 5G Mobile Networks

With an increasing demand for new generation mobile networks, ITU Radiocommunication Sector (ITU-R) has set forth key technical performance requirements for the development of the IMT-2020 system, also known as the fifth generation (5G) system [1], and has started to invite submissions of candidate radio interface technologies for IMT2020 [2]. To ensure that IMT-2020's requirements can be met, the submitted candidate radio interface technologies will be evaluated by independent evaluation groups under the evaluation guidelines of Report ITU-R M.EIMT-2020. EVAL1 [3], where system -level simulation is employed as the major tool for the performance evaluation of various application scenarios.

Maximum Likelihood Time Delay Estimation From Single- and Multi-Carrier DSSS Multipath MIMO Transmissions for Future 5G Networks

In this paper, we address the problem of time delay estimation (TDE) from single-carrier (SC) or multi-carrier (MC) direct-sequence spread spectrum (DSSS) multipath transmissions in the presence of multiple transmit and/or receive antennas that will characterize future 5G radio interface technologies (RITs), such as coded-domain nonorthogonal multiple access. We derive for the first time a closed-form expression for the Cramer-Rao lower bound (CRLB) and develop two maximum likelihood (ML) multipath TDEs for SC DSSS single-input multiple-output (SIMO) in the non-data-aided (NDA) case. The first TDE, based on iterative expectation maximization (EM), provides accurate estimates whenever a good initial guess of the parameters is available at the receiver. The second TDE implements the ML criterion in a non-iterative way and finds the global maximum of the compressed likelihood function using the importance sampling (IS) technique without requiring any initialization. We also extend both the SC DSSS SIMO CRLB and the two new SC DSSS SIMO ML NDA TDEs to MC DSSS RITs and to multiple-input multiple-output structures with any diversity versus multiplexing pre-coding type before generalizing them all to the data-aided (DA) case. Simulations suggest that the EM TDE is suitable for large observation in space, time, and/or frequency, whereas the IS TDE is preferred in the opposite case of very short data records. Moreover, we show in the NDA case, both analytically and by simulations, that spatial (transmit and receive), temporal, and frequency samples interchangeably have the same impact on estimation accuracy and performance bound regardless of the channel correlation type and amount present in each dimension. Furthermore, we are able to properly cope with such channel correlations that do indeed arise in practice and, hence, become very challenging both in estimation and CRLB derivation in the DA case, but that have been so far overlooked in previous works.

Trade-Off Between Power and Bandwidth Consumption in a Reconfigurable Xhaul Network Architecture

The increasing number of wireless devices, the high required traffic bandwidth, and power consumption will lead to a revolution of mobile access networks, which is not a simple evolution of traditional ones. Cloud radio access network technologies are seen as promising solution in order to deal with the heavy requirements defined for 5G mobile networks. The introduction of the common public radio interface (CPRI) technology allows for a centralization in BaseBand unit (BBU) of some access functions with advantages in terms of power consumption saving when switching off algorithms are implemented. Unfortunately, the advantages of the CPRI technology are to be paid with an increase in required bandwidth to carry the traffic between the BBU and the radio remote unit (RRU), in which only the radio functions are implemented. For this reason, a tradeoff solution between power and bandwidth consumption is proposed and evaluated. The proposed solution consists of: 1) handling the traffic generated by the users through both RRU and traditional radio base stations (RBS) and 2) carrying the traffic generated by the RRU and RBS (CPRI and Ethernet flows) with a reconfigurable network. The proposed solution is investigated under the lognormal spatial traffic distribution assumption. After proposing resource dimensioning analytical models validated by simulation, we show how the sum of the bandwidth and power consumption may be minimized with the deployment of a given percentage of RRU. For instance we show how in 5G traffic scenarios this percentage can vary from 30% to 50% according to total traffic amount handled by a switching node of the reconfigurable network.

Evaluation of system performance for the BMSat

SummaryIn recent years, geostationary Earth orbit mobile satellite communications has seen rapid development. The satellite/terrestrial integrated communication networks with Long‐Term Evolution technology have become a research emphasis. China proposed the Radio Interface Technology of Broadband Multimedia Satellite (BMSat) as a candidate to be considered as the satellite component of International Mobile Telecommunications Advanced. To show the feasibility of the BMSat system before implementation, this paper presents a complete simulation of the system performance in different communication scenarios and terminal types specified by the International Telecommunication Union. We also provide a corresponding theoretical analysis and simulation data for practical applications and the future research. Copyright © 2015 John Wiley &amp; Sons, Ltd.

English

The 3GPP long term evolution (3GPP-LTE) has adopted the Discrete Fourier Transform Spreading Orthogonal Frequency Division Multiple Access (DFTS-OFDMA) technique to be used in the uplink air interface for the next generation cellular systems. The DFTS-OFDMA is also a candidate of radio interface technologies for the IMT-Advanced standards in ITU-R. This technique has been adopted for uplink transmission due to its attractive feature of lower PAPR archived by precoding data symbols using a DFT operation at the transmitter. In this paper, we analyse the performance of DFT-Spreading OFDMA technique in PAPR reduction by using the IFDMA and LFDMA subcarriers mapping modes. We also analyse the performance of the DFTS OFDMA technique for PAPR reduction as the number of subcarriers allocated to each user varies, specifically with the LFDMA subcarriers mapping mode. Simulation results show that, the IFDMA improves PAPR performance significantly than LFDMA with pulse shaping and wihout pulse shaping but at a cost of increased bandwidth.Moreover, the performance of DFT-Spreading with LFDMA improves when the number of subcarriers allocated to users becomes small. Although, in-terms of PAPR power efficiency, the IFDMA performs better than LFDMA allocation scheme, but LFDMA is very superior in terms of throughput when channel dependent scheduling is utilized and has been widely implemented in LTE.

Wireless World 2020: Radio Interface Challenges and Technology Enablers

Future pervasive communication system requirements for two to three orders of magnitude capacity improvement, flexible, fast deployment, and cost/energy efficiency are expected to revolutionize the way we design and use wireless networks. From a network infrastructure perspective, the emphasis is placed on achieving ubiquitous, real-time high data rate communications ?anytime-anywhere,? including at cell-edge, through Small Cell Network architectures and Heterogeneous Cellular Networks (HetNets). From a pervasive systems? perspective, the vision of the Internet of Things suggests the integration between ubiquitous computing and wireless communications targeting a reliable connectivity of things, i.e., computers, sensors, and everyday objects equipped with transceivers. From a backhaul bandwidth, network resource sharing, and optimization perspective, cloud-based processing and radio access network virtualization provide a revolutionary approach toward balancing the degree of centralization of physical and virtual resources management. In this article we analyze these three trends, present key technology enablers, and assess suitable performance merits in an effort to set the scene for the wireless evolution in the era beyond 2020.

LTE-satellite: Chinese proposal for satellite component of IMT-Advanced system

As a complementary to terrestrial mobile communication systems, mobile satellite communication system can fill the gaps that cannot be covered by terrestrial network, and provides an irreplaceable solution for emergency communication in disaster. To pave the road for future satellite/terrestrial integrated communication networks, ITU-R invited proposals for candidate Radio Interface Technology (RIT) for the satellite component of International Mobile Telecommunications (IMT)-Advanced. China proposed the RIT of Long Term Evolution (LTE)-satellite as a candidate to be considered as IMT-Advanced satellite technology. The submitted LTE-satellite candidate RIT is specified based on terrestrial LTE-Advanced FDD standards that are developed in 3GPP. Considering satellite requirements, a number of modifications to LTE-Advanced are made to adapt to satellite radio transmission environments. This paper provides a general introduction of the new characteristics of LTE-satellite.

Interference-Avoidance Techniques: Improving Ubiquitous User Experience

This article presents interference- avoidance schemes developed in the Advanced Radio Interface Technologies for [Fourth Generation (4G)] Systems (ARTIST4G) Project for three scenarios targeting the deployment of Third-Generation Partnership Project (3GPP), long-term evolution (LTE)-advanced networks, and beyond. In the first scenario, we propose three-dimensional (3-D) beamforming as a flexible technology for taking the best benefit from the internode cooperation, constrained by the core network infrastructure. The second scenario addresses a long-term deployment with nonconstrained internodes cooperation link based on an interference-shaping strategy that allows for exploiting at its maximum the coordinated multipoint concept. Finally, we investigate interference coordination mechanisms for protecting the macro network from a massive deployment of small cells that provides a network capacity increase by high offloading capabilities.

Publish/subscribe delay-tolerant message-oriented middleware for resilient communication

The rapid growth of wireless technologies has resulted in mobile phones and wireless devices becoming essential and ubiquitous elements in everyday domestic and business activity. Wireless devices are also used by emergency and support services. While wireless communication is more flexible than wired communication, it is often not robust, and the coverage is not always complete. In this article, we describe a mobile middleware architecture using delay-tolerant network (DTN) technology, and publish/subscribe concepts. The purpose of the middleware is to add resilience and reach to wireless communications, and reduce battery drainage of the mobile devices and hence extend operational lifetime. The same technology has the potential to provide a fallback communication platform providing greater penetration than that which would otherwise be available in situations where the conventional cellular structure is no longer working or access is limited. It can enable mobile users to connect through the help of multiple radio interface technologies and to exploit physical movement using the inherent relaying capability of DTNs. The approach exploits the synergy between publish/subscribe message-oriented middleware (MOM) and DTN, as neither requires an end-to-end connection at one moment in time. Scenarios based on exploiting any available connection, communication even when there is extreme wireless coverage failure, and a prototype developed on the Android mobile platform are presented. Some relevant issues are also analyzed related to the practical deployment, viz. message routing, energy efficiency, and security.