Digital Radio Research Articles

An experimental study on beamforming architecture and full-duplex wireless across two operational outdoor massive MIMO networks

Full-duplex (FD) wireless communication refers to a communication system in which both ends of a wireless link transmit and receive data simultaneously in the same frequency band. One of the major challenges of FD communication is self-interference (SI), which refers to the interference caused by transmitting elements of a radio to its own receiving elements. Fully digital beamforming is a technique used to conduct beamforming and has been recently repurposed to also reduce SI. However, the cost of fully digital systems dramatically increases with the number of antennas, as each antenna requires an independent Tx-Rx RF chain. Hybrid beamforming systems use a much smaller number of RF chains to feed the same number of antennas, and hence can significantly reduce the deployment cost. In this paper, we aim to quantify the performance gap between these two radio architectures in terms of SI cancellation and system capacity in FD multi-user Multiple Input Multiple Output (MIMO) setups. We first obtained over-the-air channel measurement data on two outdoor massive MIMO deployments over the course of three months. We next study SoftNull and M-HBFD as two state-of-the-art transmit (Tx) beamforming based FD systems, and introduce two new joint transmit-receive (Tx-Rx) beamforming based FD systems named TR-FD2 and TR-HBFD for fully digital and hybrid radio architectures, respectively. We show that the hybrid beamforming systems can achieve 80%–99% of the fully digital systems capacity, depending on the number of users. Our results show that it is possible to get many benefits associated with fully digital massive MIMO systems with a hybrid beamforming architecture at a fraction of the cost.

Spatial Channel State Information Prediction With Generative AI: Toward Holographic Communication and Digital Radio Twin

Spatial Channel State Information Prediction With Generative AI: Toward Holographic Communication and Digital Radio Twin

Enhancing Digital Forensics Readiness in Big Data Wireless Medical Networks: A Secure Decentralised Framework

Wireless medical networks are pivotal for chronic disease management, yet the sensitive Big Data they generate presents administration challenges and cyber vulnerability. This Big Data is valuable within both healthcare and legal contexts, serving as a resource for investigating medical malpractice, civil cases, criminal activities, and network-related incidents. However, the rapid evolution of network technologies and data creates complexities in digital forensics investigations and audits. To address these issues, this paper proposes a secure decentralised framework aimed at bolstering digital forensics readiness (DFR) in Big Data wireless medical networks by identifying security threats, complexities, and gaps in current research efforts. By improving the network's resilience to cyber threats and aiding in medical malpractice investigations, this framework significantly advances digital forensics, wireless networks, and healthcare. It enhances digital forensics readiness, incident response, and the management of medical malpractice incidents in Big Data wireless medical networks. A real-world scenario-based evaluation demonstrated the framework's effectiveness in improving forensic readiness and response capabilities, validating its practical applicability and impact. A comparison of the proposed framework with existing frameworks concluded that it is an advancement in framework design for DFR, especially in regard to Big Data processing, decentralised DFR storage and scalability.

Objective assessment of the speech quality broadcasted by local Digital Radio in selected locations in Wroclaw

Objective assessment of the speech quality broadcasted by local Digital Radio in selected locations in Wroclaw

Analysis of Differences in the Signal Reflected from an Aircraft and Simulated Interference in an Application to Radar Protection

The creation of DRFM (Digital Radio Frequency Memory) technology is a revolutionary step in the development of simulating interference techniques. The technology made it possible to transform the received signal with high quality, make the necessary changes to it and emit it in the form of simulating interference. Currently, a high level of imitation of radar signals reflected from real objects has been achieved. The basis for counteracting such interference is a detailed analysis of the differences between the real reflected signal and simulating interference. In this regard, a mathematical model of a signal reflected from a spatially distributed object is considered before and after frequency conversion to video frequency. Based on the analysis of typical variants of interference generation, mathematical models of simulating interference are considered, providing various degrees of similarity to the reflected signal. The results of the model analysis are the basis for constructing algorithms for protecting radar stations from simulating interference.

Digitalized Radio over Fiber Network-Based Sigma Delta Modulation

ABSTRACT Digital Radio over Fiber (DRoF) technologies end up being the most often used option for the backbone of Wide Area Networks (WAN). The main goal of this paper is to evaluate a DRoF scheme called Sigma Delta Radio over Fiber (SDRoF). Studies have been done on the suggested system performance metrics, such as Error Vector Magnitude (EVM). According to the simulation findings, the suggested model can handle 6.144 Gbps data transfer up to 300 km with zero BER and an EVM of about 4.153%. The proposed system model was found to be superior to the most recent peer-reviewed papers.

Auditory Learner

Auditory Learner

Digital Radio in Bulgaria – Challenges and Prospects

The article looks upon the development of digital technologies for radio broadcasting in Europe and North America, as an alternative or as a supplement to the existing analog distribution; the advantages and disadvantages of digital distribution; the legal basis of this type of broadcasting and we make the relevant conclusions and recommendations from the point of view of the radio industry.

Shapley’s Value as a Resource Optimization Strategy for Digital Radio Transmission over IBOC FM

The hybrid in-band on-channel (IBOC) transmission system, which serves as a digital audio radio scheme, facilitates the simultaneous transmission of analog FM and digital audio. In IBOC systems, broadcasters transmit signals within allocated channel bands, posing a challenge in bandwidth allocation for digital audio transmission. To address this, cooperative game theory, supported by the bankruptcy game and Shapley’s value, is proposed as a strategy to optimize bandwidth allocation at each node or station. This approach considers service demand, the number of stations, and radio channel conditions in the FM band. The paper presents a scenario under saturated traffic conditions to evaluate the degree of optimization achievable using the Shapley value under clearly defined traffic and channel conditions. The results indicate that cooperative game theory, with the support of the Shapley value, offers an excellent alternative for optimizing bandwidth in digital broadcasting over IBOC in FM, with potential applicability in other digital radio broadcasting systems.

Expotecnología 2022

Expotecnología 2022 was an event that took place in the city of Cartagena de Indias, from November 2 to 6, 2022, with the slogan “The future of engineering in the face of technological disruption” This eighteenth version was a meeting that brought together the scientific and academic community in spaces for the dissemination and transfer of knowledge, where innovation was the essence and a fundamental part of the event. Expotecnología was created in the Faculty of Engineering Sciences - FACI, of the Antonio de Arévalo University Foundation - UNITECNAR and in this version it maintained as mission, the development of the interaction between science, technology and society, through establishing of knowledge networks and academic and professional cooperation. The main objective was to address the challenges that emerge from the everyday life of the engineering community, the problems immersed in the development of projects and programs of Higher Education Institutions (IES), organizations and research centers at the national and international level. In the development of the day of presentations in a virtual way, it was possible to promote the dissemination of the research work of professionals, teachers and students from all areas of engineering, framed in four (4) thematic axes, as follows:• New technologies: Big data, Artificial Intelligence, Business Intelligence, Software Engineering, Education and new technologies and Mobile Applications.• Petrochemicals and process control: Materials Science, Instrumentation and Control Systems, Robotics and Automation and Industrial Maintenance.• Electricity, electronics and telecommunications: IoT, Fiber optics, Digital Signal Processing, Wireless Networks, Mobile Communications, Power Systems, Energy Storage, Smart Grids, Renewable Energies, Operation and Distribution, Energy Dispatch, Energy Markets• Construction Summit: Modern Building Systems and Computational Modeling.On this occasion, the event was attended by 512 people, representatives from 25 national and 6 international universities. 32 presentations were made, of which 32 articles were selected for this volume of the IOP Conference Cycle: Materials Science and Engineering and 13 articles for the book Engineering, Innovation and the fourth industrial revolution., After a process of Peer Review. The plenary conferences were in charge of 2 national and 8 international speakers .List of Invited speakers, Organizing Committee, Special thanks are available in this pdf.

FFT-Based Simultaneous Calculations of Very Long Signal Multi-Resolution Spectra for Ultra-Wideband Digital Radio Frequency Receiver and Other Digital Sensor Applications.

The discrete Fourier transform (DFT) is the most commonly used signal processing method in modern digital sensor design for signal study and analysis. It is often implemented in hardware, such as a field programmable gate array (FPGA), using the fast Fourier transform (FFT) algorithm. The frequency resolution (i.e., frequency bin size) is determined by the number of time samples used in the DFT, when the digital sensor's bandwidth is fixed. One can vary the sensitivity of a radio frequency receiver by changing the number of time samples used in the DFT. As the number of samples increases, the frequency bin width decreases, and the digital receiver sensitivity increases. In some applications, it is useful to compute an ensemble of FFT lengths; e.g., 2P-j for j=0, 1, 2, …, J, where j is defined as the spectrum level with frequency resolution 2j·Δf. Here Δf is the frequency resolution at j=0. However, calculating all of these spectra one by one using the conventional FFT method would be prohibitively time-consuming, even on a modern FPGA. This is especially true for large values of P; e.g., P≥20. The goal of this communication is to introduce a new method that can produce multi-resolution spectrum lines corresponding to sample lengths 2P-j for all J+1 levels, concurrently, while one long 2P-length FFT is being calculated. That is, the lower resolution spectra are generated naturally as by-products during the computation of the 2P-length FFT, so there is no need to perform additional calculations in order to obtain them.

Design of A Chaos-based Digital Radio over Fiber Transmission Link using ASK Modulation for Wireless Communication Systems

Secured broadband radio communications are becoming increasingly pivotal for high-speed connectivity in radio access networks, playing a crucial role in both mobile information systems and wireless IoT connections. This paper introduces a chaos-based two-channel digital radio communication system utilizing fiber optic radio transmission technology. The system comprises two radio channels operating at up to 1 Gbps using amplitude shift keying (ASK) modulation, followed by modulation with a chaotic sequence before conversion to the optical domain using the MZM modulator. To compensate for fiber loss, the system utilizes an Erbium Doped Fiber Amplifier (EDFA) and employs the optical links through standard ITU-G.655 optical fibers. Numerical simulation of the designed system is performed using the commercialized simulation software Optisystem V.15 to assess and characterize transmission performance. The results demonstrate the system’s effective operation on two channels with a fiber transmission distance of up to 110 km, maintaining a bit error ratio of less than 10−9. This feature ensures reliable performance for high-speed radio connections, particularly in applications such as fronthaul networks in cloud radio access and wireless sensor network connections.

Организация поездной радиосвязи и передачи данных в технологии «виртуальная сцепка» в одном цифровом радиоканале

Despite the fact that train radio communication and the virtual coupling technology should ensure traffic safety, so far the development of these systems on Russian railways is taking place in unrelated directions. Currently, train radio communication is analog, organized in the hectometer frequency range (2.13 and 2.15 MHz), its quality and reliability need to be improved. The transition to digital standards is slow, as it requires significant capital investments in infrastructure construction. Considering the virtual coupling technology, it is currently being tested using digital radio communication channels. The article discusses measures that will allow creating the single data transmission network using virtual coupling technology and train radio communication in one digital radio channel on an existing infrastructure. It will ensure a reduction in capital investments in the organization of the communication system, as well as increase its reliability, quality and throughput.

COEXISTENCE OF TELEVISION BROADCASTING, FM BROADCASTING, DIGITAL BROADCASTING IN DAB AND DRM+ STANDARDS CALCULATION METHODOLOGY

The model parameters of analogue and digital radio and TV broadcasting networks are determined on the basis of data on frequency assignments to radio broadcasting stations using information on issued permits for the use of radio frequency channels of existing and planned radio broadcasting stations. The parameters of the network model are also determined on the basis of data contained in the database on frequency assignments of a radio frequency service organization or radio frequency application materials for obtaining an EMC examination conclusion submitted to a radio frequency service organization to obtain permission to use frequency blocks / radio frequency channels for the declared radio broadcasting stations. The problem of sharing the spectrum in the VHF band by terrestrial digital television broadcasting services (DVB-T standard, etc.), analogue television broadcasting, analogue FM audio broadcasting, digital audio broadcasting DAB/DAB+, DRM+ and RAVIS and the conditions for them coexistence are considered. Compatibility criteria and calculation algorithm are considered. Compatibility criteria and calculation algorithm are considered. Directions for further research are presented.

Influence of Jets on [O iii] Extensions in Green Pea/Bean Galaxies

We present a study investigating the influence of jets on galaxies exhibiting strong [O iii]λ5007 emission, known as Green Peas and Green Beans. Our sample comprised 12 nearby sources (z ∼ 0.04–0.1, six with jets and six without jets) with high [O iii] luminosity (L ∼ 1040 erg s−1), selected from a radio-selected galaxy sample observed with the Sloan Digital Sky Survey and Radio Sky at Twenty-centimeters survey. We perform Large Binocular Telescope–Multi-Object Double Spectrograph long-slit spectroscopy at two position angles for each galaxy: one aligned with the jet direction and another perpendicular to it. By tracing the [O iii] emission along these slits, we aimed to assess the extension of the narrow line region and examine the impact of jets. Surprisingly, our analysis revealed no preferred direction for the extension of the [O iii] emission, indicating that jets have a limited influence on the extended emission line regions (EELRs). This also suggests the possibility of missed detection of conical-shaped EELRs aligned with the jets, attributable to our slit orientations. Furthermore, we compared the extension of [O ii] emission, which traces star-forming regions, with that of [O iii]. We observed a significant difference, with [O ii] exhibiting a considerably greater extension along the galactic plane. This suggests a stronger association of [O ii] emission with stellar processes.

Security Issues in Special-Purpose Digital Radio Communication Systems: A Systematic Review

Security Issues in Special-Purpose Digital Radio Communication Systems: A Systematic Review

Optimization of Resources for Digital Radio Transmission Over IBOC FM Through Max-min Fairness

Optimization of Resources for Digital Radio Transmission Over IBOC FM Through Max-min Fairness

ASSESSMENT OF BROADCAST JOURNALISTS’ KNOWLEDGE AND UTILIZATION OF DIGITAL BROADCAST EQUIPMENT: A CASE STUDY OF DELTA BROADCASTING SERVICE, ASABA

In November 2017, the Delta State government commissioned the digital radio and TV studio of the Delta Broadcasting Service in Asaba. The implication of this is that the analogue equipment in the station will have to gradually give way to the digital ones. Although the government of Delta State has not provided sufficient digital broadcast facilities for the broadcast journalists, it is expected that practicing journalists will become knowledgeable and key into the new development by learning the use of the digital broadcast equipment, regardless of the government provisions. Hence, the study interrogated the level of knowledge and utilization of digital broadcast equipment and also the challenges facing the use of digital broadcast equipment among broadcast journalists in Delta State Broadcasting Service. Four major variables, namely, knowledge, utilization, challenges, and solutions, were placed under scrutiny using the census sampling procedure of a survey to examine 100 respondents spread across two departments in DBS, Asaba. The study found, amongst many other things, that there is a high level of knowledge and utilization among journalists in DBS, Asaba, as regards digital broadcast equipment, while inadequate skilled manpower, funds, training, and equipment were the major challenges facing the use of digital equipment in the station. The study therefore recommended that there is a need to intensify training and retraining of digital broadcast journalists and that the government and well-meaning people of Delta prioritize the funding of digital equipment at the station.

Using a portable protected transmission software and hardware complex «pd-300» data in the control system divisions of the internal affairs bodies

The article discusses current issues related to the problem of the outdated fleet of radio communications equipment available in the arsenal of departments of internal affairs bodies, as well as the variety of technologies on the basis of which portable radio equipment is built. Currently, law enforcement agencies simultaneously use both analog and digital radio stations of FM, DMR, TETRA and APCO P25 standards. The radio communication means used are not always able to fulfill the requirements for timeliness and security of transmitted and received operationally significant information during operational investigative activities. Failure to comply with the above requirements will inevitably lead to the inability to manage units, and as a consequence to the failure of operational-search activities.

Dynamic Range of a Digital Radio Receiver with a Photonic Analog-to-Digital Converter

The article is devoted to determining the requirements for the preliminary, analog part of the receiver and its structure when using a photonic ADC. The subject of research in this case is the issues of ensuring a large dynamic range of signals at the input of a receiver with a photonic ADC. The parameters and properties of the PADC with optical quantization and discretization are investigated. The distinctive features of the PADC are a high sampling rate, about 100 GHz, the possibility of increasing the carrier-to-noise ratio (CNR) and the effective number of bits (ENOB) due to the amplification of the carrier or modulating signal, and a low noise factor of microwave photonic elements. The presented advantages make it possible to reduce the structure of the analog part of the receiver by eliminating the mixer and anti-aliasing filter, as well as to achieve better sensitivity due to a lower level of internal noise. The study also revealed a limitation of the dynamic range imposed by the photonic element base. The reason for the limitation is the nonlinearity of the electro-optical modulators used and the limitation of the upper limit of the dynamic range to the photodetectors used. All this leads to requirements under which the analog part must provide significant amplification of the received radio signal, as well as the implementation of a variable gain. As a result, structural solutions are presented in the form of multichannel switching circuits. The principle of operation lies in the fact that each channel, consisting of a cascade of linear amplifiers and a PADC, has a different gain, and in the digital processing unit, channels are compared and switched depending on the signal level. At the same time, the level should be in the 'corridor' of acceptable values for the application of the PADC and within the dynamic range. The presented structural solutions will make it possible to implement radio receivers capable of receiving and processing a microwave signal without transferring the signal to an intermediate frequency. At the same time, the required signal amplification level of 105 - 106 can be achieved, which makes it possible to achieve a signal level of 2.5-9.5 V, at which the photonic analog-to-digital converter has the best CNR and ENOB indicators.