Radio Subsystem Research Articles

Wireless sensor system for real-time performance monitoring in sports

In Paralympic sports, investigating seating ergonomics and optimizing for performance is crucial due to individual impairments. Usually, experiments are conducted in laboratory environments and for skiing, usually on a treadmill. In this paper, we are moving experiments out of the laboratory setting to in-slope performance monitoring of kinetics and kinematics. A wireless sensor system is developed and validated in terms of delay. The results show a median delay of 52 ms for the wired main system and 53 ms for the wireless sub-system. The sensor system was implemented on a highly adjustable Paralympic sit-ski, and an experiment was conducted to pinpoint optimal equipment settings for an individual athlete. In addition, the system provided force data from both knees, seat, belt, and both poles. The data collected can also be used to analyze the technique, in addition to assisting in the classification process in the LW10–12 class. The proposed system design also allows for adding a vast amount of different sensor types, and by testing for delay, synchronized with well-known GNSS and IMU sensors already used in many sports to analyze athlete performance.

ESTIMATION OF POTENTIAL PARAMETERS FOR 5G MOBILE NETWORKS RADIOCHANNELS

Background. Deploying of 5G mobile networks opens up wide opportunities for the development of IoT, high-speed access to Internet services, industrial automation, telemedicine and other modern services. Peak transmission rate, latency, and spectral efficiency are important indicators for network performance. These indicators are primarily determined by the 5G-NR radio subsystem, which is built using modern technologies such as OFDM, interference-resistant LDPC coding and massive MIMO antenna systems. In addition, frames and time-frequency resource distribution in 5G-NR are improved for both Downlink and Uplink. All of these are described in various 3GPPP documents, but to evaluate these indicators, it is necessary to create an appropriate methodology and perform calculations.
 Objective. The purpose of the research is to create a methodology and estimate the potential values of peak transmission rate, latency and spectral efficiency of 5G-NR radio channels.
 Method. Analytical calculation methods based on recommendations and source data of 3GPP documents are used.
 Results. Analytical studies show that 5G-NR radio channels can potentially provide a peak transmission up to 37 Gbps, latency less than 0.5ms, and spectral efficiency up to 46 bps/Hz rate in the Downlink direction using 50 MHz FR1 frequency band, QAM256 modulation and MIMO 8 x 8-antenna system.
 Conclusions. The researched 5G-NR radio channels efficiency indicators meet current and future services requirements.

Dynamic Resource Optimization for Energy-Efficient 6G-IoT Ecosystems

The problem of energy optimization for Internet of Things (IoT) devices is crucial for two reasons. Firstly, IoT devices powered by renewable energy sources have limited energy resources. Secondly, the aggregate energy requirement for these small and low-powered devices is translated into significant energy consumption. Existing works show that a significant portion of an IoT device’s energy is consumed by the radio sub-system. With the emerging sixth generation (6G), energy efficiency is a major design criterion for significantly increasing the IoT network’s performance. To solve this issue, this paper focuses on maximizing the energy efficiency of the radio sub-system. In wireless communications, the channel plays a major role in determining energy requirements. Therefore, a mixed-integer nonlinear programming problem is formulated to jointly optimize power allocation, sub-channel allocation, user selection, and the activated remote radio units (RRUs) in a combinatorial approach according to the channel conditions. Although it is an NP-hard problem, the optimization problem is solved through fractional programming properties, converting it into an equivalent tractable and parametric form. The resulting problem is then solved optimally by using the Lagrangian decomposition method and an improved Kuhn–Munkres algorithm. The results show that the proposed technique significantly improves the energy efficiency of IoT systems as compared to the state-of-the-art work.

EVALUATION OF VOICE TRANSMISSION QUALITY IN THE LTE NETWORKS

Background. LTE mobile networks combine packet network technology and radio technology. Parameters of packet and radio subsystems significantly affects the quality of all traffic types transmission, especially telephone traffic, as the most demanding to such parameters of network transmission as delay, jitter and packet loss rate. The recommendations of the International Telecommunication Union and the documents of the partner organization of telecommunications operators (3GPP) contain hypothetical reference models, targets for end-to-end connection quality, and lists the factors that affect the quality (QoS) of VoLTE services. In addition, the network points are shown where you need to measure the quality of telephone traffic and tools for quality assessment. The quality of telephony services is assessed according to the E-model using the method of determining the mean opinion score (MOS). However, this technique is intended primarily to determine the MOS during the network planning. To calculate the MOS in a working network, you have to measure such network performance first such as voice delay and packet loss rate. This article presents the method of calculating MOS in the LTE network based on the E-model and presents the results of practical quality studies.
 Objective. The purpose of this article is research the impact of delay and packet loss ratio and voice codec characteristics in the real LTE network on quality of telephone services.
 Methods. Analysis of factors affecting on telephone services quality and analysis MOS assessment methods. Practical studies of the delay and packet loss ratio affect the MOS level in various conditions of radio coverage and network load.
 Results. Practical results of delay and packet loss ratio influence on the telephone services quality in the LTE network. Calculated MOS based on the practically measured delay and packet loss ratio.
 Conclusions. The combination of packet technologies, modern AMR-WB codecs and QoS support mechanisms in the LTE networks provides high quality perception of voice messages at the level of not less than 4 on the MOS scale. With a delay not exceeding 180 ms, a sufficiently high quality of voice transmission is ensured (MOS ≈ 4). VoLTE technology using the AMR-WB codec is quite resistant to packet loss and provides high quality perception of voice messages at a packet loss ratio of up to 1%.

Human Recognition using Single-Input-Single-Output Channel Model and Support Vector Machines

WiFi based human motion recognition systems mainly rely on the availability of Channel State Information (CSI). Embedded within WiFi devices, the present radio sub-systems can output CSI that describes the response of a wireless communication channel. Radio subsystems as such, use complex hardware architectures that consume lots of energy during data transmission, as well as exhibit phase drift in the sub-carriers. Although human motion recognition (HMR) based on multi-carrier transmission systems show better classification accuracy, transmission of multiple sub-carriers results in an increase in the overall energy consumption at the transmitter. Apparently CSI based systems can be perceived as process intensive and power hungry devices. To alleviate the process intensive computing and reduce energy consumption in WiFi, this study proposes a human recognition system that uses only one radio carrier frequency. The study uses two software defined radios and a machine learning classifier to identify four humans, and the study results show that human identification is possible with 99% accuracy using only one radio carrier. The results of this study will have an impact on the development process of smart sensing systems, particularly those that relate to healthcare, authentication, and passive monitoring and sensing.

Development and research of Wi-Fi network for receiving and transmitting telemechanical information in the training laboratory

The article deals with the issues of research, development and implementation of local area wireless networks in the educational process, especially with the study of the signal level for data transmission control of the local wireless network indoors. The controlled telemechanics unit uses wired systems for communication of the operator with various sensors and actuators, which creates certain difficulties and risks for the operator working in site of the telemechanics unit. The article considers a potential use of wireless technologies in the educational process, which demonstrates how to secure the operator and reduce the time to bypass all the sensors of the actuators, as well as to develop a short-range wireless subsystem.

On the Use of Glint-Doppler-Azimuth Correlation for Speed Estimation of Nearby Tangential Targets

This article introduces a new radar architecture, which implements a new signal processing scheme, with applications to the Intelligent Transportation Systems. The proposed solution exploits a well-known problem regarding low range radar systems, the Glint Effect, in order to improve previous results. For that purpose, the presented system is required to measure azimuth and Doppler of targets, for which it opts for a 2-channel Digital Array Receiver scheme working with a frequency-modulated continuous wave. This involves more complex hardware and signal processing software, comparing to the common mono-channel non coherent systems, nevertheless latest devices (radio frequency subsystems, field-programmable gate arrays, digitizers, etc) make it simple and affordable. The proposed system, with an easy-and-fast side-looking installation, exploits several advantages of its 2-channel synchronous architecture (e.g. clutter cancellation, Doppler history availability, etc) to achieve a better estimation of two key measurements: traffic flow (instantaneous and average) and vehicles speed.

A Resonant Capacitive Coupling WPT-Based Method to Power and Monitor Seat Belt Buckle Switch Status in Removable and Interchangeable Seats

<div class="section abstract"><div class="htmlview paragraph">In this study, we present an intelligent and wireless subsystem for powering and communicating with three sets of seat belt buckle sensors that are each installed on removable and interchangeable automobile seating. As automobile intelligence systems advance, a logical step is for the driver’s dashboard to display seat belt buckle indicators for rear seating in addition to the front seating. The problem encountered is that removable and interchangeable automobile seating outfitted with wired power and data links are inherently less reliable than rigidly fixed seating, as there is a risk of damage to the detachable power and data connectors throughout end-user seating removal/re-installation cycles. The present study tackles this issue through outfitting three removable and interchangeable rear seat assemblies with resonant capacitive coupling wireless power transfer as to power each rear seat across a variable gap between the interior paneling and that side of the seat closest to the interior paneling. A fundamental design challenge this system presented was the need to develop a rugged method to account for different sizes of seating, and hence to accommodate variable wireless power gaps. This issue was addressed via use of impedance matching technology to present a nearly constant load impedance to the dc-to-radiofrequency power inverter. The wirelessly received power enabled additional electronics added to the rear seat assemblies to wirelessly communicate the seat belt buckle states to a central hub where it was displayed via a custom graphical interface. Our approach involved the visibly imperceptible integration of resonant capacitively-coupled transmitting and receiving antennae behind the interior paneling for the transmitter and underneath the outer fabric of the rear seating. The resulting subsystem demonstrated the ability to power both the seat belt buckle switches and wireless communication over a range of wireless power gaps.</div></div>

Functionalized Metamaterials Enable Frequency and Polarization Agility in a Miniaturized Lightweight Antenna Package

Electromagnetic metamaterials share a perceived disadvantage with miniature radio communication antennas: limited operating bandwidths. In conventional radio systems, tuning has been confined to the radio, requiring broadband antennas and materials. With the advent of software defined and digital radios, adding the antenna into the plethora of tunable radio subsystems can become a reasonable proposition, allowing miniaturized antennas with narrow instantaneous (channel) bandwidths to be tuned across entire communications bands, depending on the channel in use. Moreover, the antenna will provide an effective filtering stage before the signal reaches the radio. The tunable metamaterial presented herein enables an antenna showcasing this functionality and more. Dramatic size reductions are made possible by a tunable, lightweight, miniaturized metamaterial. Tuning the metamaterial and antenna in tandem provides a dynamic operating channel, with a tunable, nearly arbitrary polarization response as an added benefit. Finally, this antenna provides one of the first examples in the literature of a practical device improved by functionalized metamaterials, which has been tested on a real‐world platform.

Research on Individual Monitoring System Based on PLC Technology

The paper presents modern PLC's network to Physiological parameter monitoring technology. In this paper a founding method and implement of the system for personal and real-time monitoring is described, including the operation of the whole system. The tests demonstrate that the system is stable, reliable as well as high timely and accuracy. This paper accords with the trend that the network is becoming the new development direction of Measurement Technology and Instrument. While the abnormal incidences happen, the system can immediately give an alarm automatically, in order to save the valued time for patients first aid. The system can monitor the patients continuancely for 24 hours. Just take the very small device of data collection and wireless transmission subsystem, the Patients can move freely in a certain area.

The creation of standards for global mobile communication: GSM and UMTS standardization from 1982 to 2000

GSM and UMTS are the leading standards for digital mobile communications with 5.4 billion users and nearly 90 percent world market share. Success factors for this development were the advanced and timely available system standards developed until the end of the 1990s in Europe. In the pioneer period (1982 to 1992) Phase 1 of the digital GSM standard was developed for the first GSM networks. GSM Phase 2 completed in 1995 provided a platform for an unlimited feature evolution. The GSM Phase 2+ program (1993 to 2000) provided new services, better speech quality and enhanced data services and made GSM a system of generation 2.5. An evolution to the Third Generation based on the GSM core network evolution and a new radio subsystem was conceived in the period from 1996 to 2000. A consensus between Europe, Japan and the North American GSM community on this concept was achieved. The standardization work required an effective global working structure. This was also necessary for the GSM work. To cover these needs, the Third Generation Partnership Project (3GPP) was created to develop globally applicable technical specifications. 3GPP exists since the end of 1998 and has developed a series of specification releases for 3G and a new 4G system (LTE).

Simple and low-cost platforms for cognitive radio experiments [Application Notes

In the decade since it was first proposed, cognitive radio (CR) has become a popular research topic. While most prototypes are based on a cognitive engine (CE) controlling a software defined radio (SDR) subsystem, in this article we present the reader with a somewhat novel CR architecture in which an RF application specific integrated circuit (ASIC) or system on a chip replaces the usual SDR portion of a CR, reducing the radio's cost, computational complexity, and size. While our work was motivated a need to develop an inexpensive CR suitable for deployment in small radio controlled (RC) model-airplane-sized unmanned aerial vehicles (UAVs), we hope the ideas presented here will be useful for engineering educators and CR researchers interested in learning about the RF and artificial intelligence (CE) aspects of CR and studying real radio behavior in live RF environments without designing and building specialized SDRs. We present a simple CR platform called SKIRL for experimentation and educational purposes, with a component cost less than US$240.

Compressed Transport of Baseband Signals in Radio Access Networks

In current wireless base station solutions it is becoming common to physically separate baseband units and radio subsystems. In many wireless technologies this architecture requires allocation of significant transport network resources. In this paper a low-latency baseband signal compression scheme is presented. The compression scheme significantly lowers the transport data rate while maintaining low levels of signal distortion, thus resulting in a lower-cost transport network. Considering the importance of packet-based networks, a number of additional novel compression schemes are proposed. They are optimized for transport networks that implement a quality-of-service (QoS) mechanism and/or multi-link transmission. The compression schemes are parameterized such that a smooth trade-off between the required signal quality and compression performance can be achieved through operator choice of the suitable parameter values. An attractive feature of these schemes is that they can be applied to different wireless technologies, with appropriate parameter settings, without disrupting the present architecture. The proposed solutions will lead to a cost-effective implementation of collocated and distributed network-centric baseband processing, coordinated multi-point (CoMP) and/or distributed antenna system (DAS) which are critical topics for the entire wireless telecommunications industry and infrastructure.

Seleção de tecnologias de comunicações no exército brasileiro utilizando os métodos multicritério de análise hierárquica, TODIM e software Sapiens

No Exército Brasileiro, as redes de comunicações apresentam características especiais. Um sistema tático de comunicação deve ser uma única estrutura lógica que integra múltiplas tecnologias, como os Subsistemas de Rádio de Combate e de Dados. Este trabalho mostra um estudo de caso para a seleção de tecnologia que atenda aos critérios descritos pelo Exército. Para priorizar seis alternativas, são aplicados dois métodos que auxiliam a tomada de decisão: o método AHP Clássico e o TODIM. No estudo com o AHP, é mostrado cada passo da metodologia até a conclusão do resultado. Com o TODIM, é usado um software de apoio ao uso do método, o Sapiens. Foram realizadas entrevistas com especialistas da área de comunicações para o levantamento das informações necessárias. Considera-se que o principal resultado desse trabalho é a construção de um processo estruturado para essa seleção e não a obtenção dos resultados em si.

Effects of Denial-of-Sleep Attacks on Wireless Sensor Network MAC Protocols

Wireless platforms are becoming less expensive and more powerful, enabling the promise of widespread use for everything from health monitoring to military sensing. Like other networks, sensor networks are vulnerable to malicious attack. However, the hardware simplicity of these devices makes defense mechanisms designed for traditional networks infeasible. This paper explores the denial-of-sleep attack, in which a sensor node's power supply is targeted. Attacks of this type can reduce the sensor lifetime from years to days and have a devastating impact on a sensor network. This paper classifies sensor network denial-of-sleep attacks in terms of an attacker's knowledge of the medium access control (MAC) layer protocol and ability to bypass authentication and encryption protocols. Attacks from each classification are then modeled to show the impacts on four sensor network MAC protocols, i.e., Sensor MAC (S-MAC), Timeout MAC (T-MAC), Berkeley MAC (B-MAC), and Gateway MAC (G-MAC). Implementations of selected attacks on S-MAC, T-MAC, and B-MAC are described and analyzed in detail to validate their effectiveness and analyze their efficiency. Our analysis shows that the most efficient attack on S-MAC can keep a cluster of nodes awake 100% of the time by an attacker that sleeps 99% of the time. Attacks on T-MAC can keep victims awake 100% of the time while the attacker sleeps 92% of the time. A framework for preventing denial-of-sleep attacks in sensor networks is also introduced. With full protocol knowledge and an ability to penetrate link-layer encryption, all wireless sensor network MAC protocols are susceptible to a full domination attack, which reduces the network lifetime to the minimum possible by maximizing the power consumption of the nodes' radio subsystem. Even without the ability to penetrate encryption, subtle attacks can be launched, which reduce the network lifetime by orders of magnitude. If sensor networks are to meet current expectations, they must be robust in the face of network attacks to include denial-of-sleep.

Extending QoS from Radio Access to an All-IP Core in 3G Networks: An Operator's Perspective

The convergence of wireless radio networks with all-IP networks has gained significant attention due to the ever increasing proliferation of IP technologies toward base stations as well as advances in air interfaces and wireless multimedia applications. Within standardization bodies, significant efforts are underway to address the support of QoS within the radio access network and Internet multimedia subsystem. For successful end-to-end application delivery, QoS and user profile unification are critical challenges, as is the intertwined policy enforcement between the IMS and the radio network. In this article we present a comprehensive analysis of QoS signaling over the integrated RAN and IMS domains. By using an imaginary service example, referred to as family media service, we analyze the specifics of end-to-end QoS invocation, control, and policy enforcement, including roaming scenarios. Based on laboratory measurements and simulations, we assess the call-setup delay, and recommend RAN and IMS signaling optimizations for delay reduction. We conclude the article by outlining open issues and proposing viable solutions.

Component-based development of radio systems and subsystems: Are we there yet? [Trends in DSP

The June 2005 "Trends in DSP" column explored the concept of component-based development for radio systems and subsystems. In this model the intermediate frequency (IF) and baseband signal processing associated with each wireless air interface standard on a given radio product are created from encapsulated software, hardware, and firmware intellectual property (IP) that can be reused from product to product.

Rosetta Radio Science Investigations (RSI)

The Rosetta spacecraft has been successfully launched on 2nd March 2004 to its new target comet 67 P/Churyumov-Gerasimenko. The science objectives of the Rosetta Radio Science Investigations (RSI) experiment address fundamental aspects of cometary physics such as the mass and bulk density of the nucleus, its gravity field, its interplanetary orbit perturbed by nongravitational forces, its size and shape, its internal structure, the composition and roughness of the nucleus surface, the abundance of large dust grains, the plasma content in the coma and the combined dust and gas mass flux. The masses of two asteroids, Steins and Lutetia, shall be determined during flybys in 2008 and 2010, respectively. Secondary objectives are the radio sounding of the solar corona during the superior conjunctions of the spacecraft with the Sun during the cruise phase. The radio carrier links of the spacecraft Telemetry, Tracking and Command (TT&C) subsystem between the orbiter and the Earth will be used for these investigations. An Ultrastable oscillator (USO) connected to both transponders of the radio subsystem serves as a stable frequency reference source for both radio downlinks at X-band (8.4 GHz) and S-band (2.3 GHz) in the one-way mode. The simultaneous and coherent dual-frequency downlinks via the High Gain Antenna (HGA) permit separation of contributions from the classical Doppler shift and the dispersive media effects caused by the motion of the spacecraft with respect to the Earth and the propagation of the signals through the dispersive media, respectively. The investigation relies on the observation of the phase, amplitude, polarization and propagation times of radio signals transmitted from the spacecraft and received with ground station antennas on Earth. The radio signals are affected by the medium through which the signals propagate (atmospheres, ionospheres, interplanetary medium, solar corona), by the gravitational influence of the planet on the spacecraft and finally by the performance of the various systems involved both on the spacecraft and on ground.

Ubiquitous homelinks based on IEEE 1394 and ultra wideband solutions

This article investigates a home entertainment and computing network proposal, which takes advantage of ultra wideband (UWB) impulse radio technology and the IEEE 1394 system. We first compare various present home networking technologies. Then we introduce an overview of the IEEE 1394 high-performance serial bus. After that, we describe the network architecture of the proposed home networking scheme, IEEE 1394-based UWB home entertainment and computing networks connected by a wireless 1394 bridge. The IEEE 1394 backbone network and UWB impulse radio subsystem are discussed in detail, as well. Summaries are also provided.

Fixed low-frequency broadband wireless access radio systems

This article provides an overview of a fixed low-frequency broadband wireless access system for point-to-multipoint voice and data applications. The operating frequency bands are from 2 to 11 GHz, and the base station can use multiple sectors and will be capable of supporting smart antenna technology. The product system requirements, design of the radio subsystem specification, as well as an analysis of microwave transmission related to current radio technologies are presented. Examples of BWA technology are provided courtesy of Harris Corporation.