Digital Communication Systems Research Articles

Estimation of radiation doses and lifetime attributable risk of radiation-induced cancer in the uterus and prostate from abdomen pelvis CT examinations.

Computed tomography (CT) scans are one of the most common radiation imaging modalities, and CT scans are rising steadily worldwide. CT has the potential to enhance radiography practice, but it also has the risk of drastically increasing patient doses. One CT procedure for the abdomen pelvis (AP) area can expose a patient's prostate or uterus to a substantial radiation dose, leading to concerns about radiation-induced cancer. This study aimed to estimate organ doses of the uterus and prostate and evaluate the lifetime attributable risk (LAR) of cancer incidence and mortality resulting from AP CT examinations. This retrospective study included 665 patients, of which 380 (57%) were female, and 285 (43%) were male. Data were collected from the picture archiving and communication system for AP CT procedures and exposure parameter data. Organ doses for the uterus and prostate were calculated using National Cancer Institute CT (NCICT) software. Based on the risk models proposed by the BEIR VII report, the calculated organ doses were used to estimate the LAR of prostate and uterus cancer incidence and mortality due to radiation exposure from AP CT procedures. The mean effective dose resulting from AP CT for females and males was 5.76 ± 3.22 (range: 1.13-12.71 mSv) and 4.37 ± 1.66 mSv (range: 1.36-8.07 mSv), respectively. The mean organ dose to the uterus was 10.86 ± 6.09 mGy (range: 2.13-24.06 mGy). The mean organ dose to the prostate was 7.00 ± 2.66 mGy (range: 2.18-12.94 mGy). The LAR of uterus and prostate cancer incidence was 1.75 ± 1.19 cases and 2.24 ± 1.06 cases per 100,000 persons, respectively. The LAR of cancer mortality rates from uterus and prostate cancers were 0.36 ± 0.22 and 0.48 ± 0.18 cases per 100,000 persons, respectively. The LAR of prostate and uterus cancer occurrence and mortality from radiation doses with AP CT procedures was low but not trivial. Therefore, efforts should be made to lower patient doses while retaining image quality. Although the minimization of the patient's radiation dose must guide clinical practice, the estimated slight increase in risk could aid in easing fears regarding well-justified AP CT procedures.

Distributed Timestamp Mechanism Based on Verifiable Delay Functions

In the data communication system, the real-time information interaction of communication device increases the risk of privacy sensitive data being tampered with. Therefore, maintaining data security is one of the most important issues in network data communication. Because the timestamp is the most important way to authenticate data in information interaction, it is very necessary to provide timestamp service in the data communication system. However, the existing centralized timestamp mechanism is difficult to provide credible timestamp service, and users can conspire with timestamping servers to forge timestamps. Therefore, this paper designs a distributed timestamp mechanism based on continuous verifiable delay functions. It utilizes multiple independent timestamp servers to provide timestamp services in a distributed model and appends the timestamp to the data once the data is generated. Thus, it can prove that the data already exists at a certain time and ensure the accuracy of the timestamp. Moreover, a digital blind signature based on elliptic curve cryptography is utilized to solve the problem of timestamp forgery in timestamp service. Finally, the security analysis of the scheme ensures the data security of data communication system and the concurrency rate of timestamp. The experimental results also show that the scheme greatly improves the efficiency of digital signatures.

A high-performance dual classifier based packet classification engine on FPGA

Security is one of the key elements of real-time communication systems, especially with the developments in digital communication systems. One of the most crucial networking activities that guards against hacking and unintentional consequences on connected devices is packet classification. The router's and other linked devices' sluggish processing speeds are a problem for implementing real-time packet classification. This paper proposes a novel parallel architecture for packet classification in routers. The design that has been suggested uses the parallelism that modern hardware technologies offer to categorize several packets at once to increase throughput, lower energy usage, and drastically lower latency. The suggested design supports multiple data reads by utilizing Dual Port RAM, or DPRAM. They have low latency performance and allow for fast rate packet lookup, making them the preferable choice for stage memory. The DPRAM provides the data to the packet scheduling module. The packets are received concurrently by the two subsequent packet splitter units. The throughput of packet classification increases as a result. In this paper, a parallel packet categorization architecture using FPGA is explored for maximizing throughput and maintain allowable latency while preserving low energy consumption. The classifier has the lowest energy efficiency of 7.2nJ and less latency of 58 ns. Its throughput may reach 668 MPPS (million packets per second).

Front Cover: Digital twin‐based online tools for electric power communication system training: Online digital twin power communication system

Front Cover: Digital twin‐based online tools for electric power communication system training: Online digital twin power communication system

Physical Design of 64-bit Multiplier and Accumulator (MAC) Unit Using Vedic Multiplier and CLA Adder

In digital signal processing, communication systems and many other applications, multiplier and accumulator units play a crucial role. This work presents an overview of 64-bit MAC Unit, where Vedic multiplier is used as multiplier unit and compared Carry select adders (CSA) and Carry look-ahead adder (CLA) which must be used for adder unit, accumulator unit consist of Parallel in parallel out (PIPO) shift registers. As a result, CLA adder to be more effective in terms of lower delay by comparing with other adders. The MAC Unit was modelled using Verilog-HDL, where its functional verification and synthesized was done using Intel Quartus Prime 21.1, which was simulated on Questa Intel FPGA 21.1. Further GDSII file was created using the cadence tool with the help of Incisive for functional simulation, Genus for synthesis and pre-layout timing analysis, and innovus for physical design. Entire study was carried out in 180nm technology from RTL-GDSII. The delay, power, area was monitored, the memory usage, Pre-Clock Tree Synthesis, Post-Clock Tree Synthesis (CTS) were noted before and after optimization of design.

Paillier Cryptography Based Message Authentication Code for IoMT Security

Health care visualization through Internet of Things (IoT) over wireless sensor network (WSN) becomes a current research attention due to medical sensor evolution of devices. The digital technology-based communication system is widely used in all application. Internet of medical thing (IoMT) assisted healthcare application ensures the continuous health monitoring of a patient and provides the early awareness of the one who is suffered without human participation. These smart medical devices may consume with limited resources and also the data generated by these devices are large in size. These IoMT based applications suffer from the issues such as security, anonymity, privacy, and interoperability. To overcome these issues, data aggregation methods are the solution that can concatenate the data generated by the sensors and forward it into the base station through fog node with efficient encryption and decryption. This article proposed a well-organized data aggregation and secured transmission approach. The data generated by the sensor are collected and compressed. Aggregator nodes (AN) received the compressed data and concatenate it. The concatenated and encrypted data is forward to fog node using the enhanced Paillier cryptography-based encryption with Message Authentication code (MAC). Fog node extracts the forwarded data from AN using Fog message extractor method (FME) with decryption. The proposed system ensures data integrity, security and also protects from security threats. This proposed model is simulated in Network Simulator 2.35 and the evaluated simulation results proves that the aggregation with MAC code will ensures the security, privacy and also reduces the communication cost. Fog node usages in between Aggregator and base station, will reduce the cloud server/base station computational overhead and storage cost. The proposed ideology is compared with existing data aggregation schemes in terms of computational cost, storage cost, communication cost and energy cost. Cost of communication takes 18.7 ms which is much lesser than existing schemes.

Stevan Berber: Discrete communication systems, Oxford University Press, 2021

The book contains the theory of discrete communication systems that are presented in the form of block schematics defined by mathematical operators. For the sake of comparison, the theory of digital communication systems is added to understand better the relations between the two theories. Two generic schemes of the systems are designed that are used to develop specific discrete and digital systems as their special cases. The complementary chapters of the book contain the theory of the continuous time and discrete-time processing of the deterministic and stochastic signal that is necessary for understanding the main chapters presenting communication systems.

PAPR Reduction in OFDM System Using Metaheuristic Algorithm

The advancement of technology necessitates the development of more sophisticated modulation strategies for wideband digital communication systems. The requirements for high-speed data transmissions can be effectively met by utilizing orthogonal frequency division multiplexing, which is an effective technique. However, a high peak-to-average power ratio (PAPR) is one of the key limits that OFDM systems face, both in terms of their performance and their power efficiency. The evaluation of the PAPR reduction has become a topic of widespread interest in this present decade due to the relevance it holds in the industrial and scientific communities. The purpose of this study is to show the combination of the bat algorithm with the partial transmit sequence scheme as an effective way for reducing PAPR that also eases the burden of computing work. For the purpose of providing a comparative evaluation of the PAPR reduction performance, a number of simulations using various partial transmit sequence schemes have been carried out. The findings of the simulation show that the BA-PTS scheme has the potential to provide superior PAPR reduction performance while simultaneously reducing the computational load.

Eisenstein field BCH codes construction and decoding

<abstract> <p>First, we will go through the theory behind the Eisenstein field (EF) and its extension field. In contrast, we provide a detailed framework for building BCH codes over the EF in the second stage. BCH codes over the EF are decoded using the Berlekamp-Massey algorithm (BMA) in this article. We investigate the error-correcting capabilities of these codes and provide expressions for minimal distance. We provide researchers and engineers creating and implementing robust error-correcting codes for digital communication systems with detailed information on building, decoding and performance assessment.</p> </abstract>

Цифрлық дәуірде артериялық гипертензиямен ауыратын науқастарды қашықтықтан бақылау және басқару

The use of active remote monitoring of patients with AH receiving antihypertensive therapy helps to achieve target BP values with subsequent monitoring of health indicators, as well as to provide timely medical care. Remote monitoring and treatment using information and communication technologies has been proposed to improve the quality of medical care. The introduction of remote BP monitoring will significantly improve the existing model of diagnostics and treatment of patients with chronic diseases, increase the number of observed patients at each therapeutic site without increasing the time for dispensary observation, as well as attract the working-age population to primary prevention of cardiovascular diseases. Taking into account modern trends in medical care for the working population and progress in information technologies, there is currently an opportunity to build a new model, which, while maintaining the main levels and stages of medical care, should ensure compliance with uniform standards of medical care, which can be ensured through the introduction of telemedicine and mobile components. The new elements of the system include: retrofitting medical stations of enterprises with medical and telecommunication equipment, connecting them to medical information systems; application of patient-oriented personal hardware and software systems for prevention, treatment monitoring and rehabilitation; use of mobile medical and telemedicine complexes; building up the material, technical and human resource capacity of emergency medical aid and medical evacuation services; development of digital communication systems between hospitals and medical centers in remote areas; and development of a new system of medical and telemedicine services. Organizational solutions in the field of digital and mobile medicine can serve as a basis for building a promising model of medical support for the working population in remote areas, ensuring proper quality and accessibility of medical care. The article considers the main aspects of using remote blood pressure monitoring as one of the methods of telemedicine health control. The regulatory and legal framework regulating the provision of medical care with the use of remote blood pressure monitoring is presented. The main technical aspects and technological models of telemedicine monitoring of BP in patients with arterial hypertension are analyzed. The review of publications devoted to clinical and economic efficiency of remote monitoring of blood pressure is given.

Simulation Design of Baseband Optimal Digital Communication System with Non-Ideal Channel

Simulation Design of Baseband Optimal Digital Communication System with Non-Ideal Channel

Maximum-Likelihood-Based Location, Orientation, Transmitted Power, and Antenna Beamwidth Estimator Utilizing the Angle-of-Arrival and Received Power for Spectrum Sharing at Millimeter Wave Bands

The fifth-generation (5G) system utilizing millimeter wave is available in Japan, but more bandwidth is demanded by the mobile phone operators to accommodate the demand for high data rate. Allocation of the vacant spectrum is impossible due to the past spectrum allocation to other radio systems. For example, 24.25-27.5 GHz has been allocated for the fixed wireless access (FWA) and license exempt small power data communication system in Japan. Although Japanese government is considering to license a part of the band for 5G under the spectrum sharing scheme, the coexistence design is quite challenging due to unavailable operation data of such systems in a form of database for the coexistence study. For this purpose, this paper introduces a maximum-likelihood estimator (MLE), which utilizes the angle-of-arrival (AoA) and received power of the line-of-sight (LOS)/diffraction paths as well as the map database to simultaneously estimate these unknown parameters via the spectrum sensing. It was applied to the measurement data obtained from a sub-urban environment where a commercial fixed wireless access system with similar operational parameters is under operation. Its performance was evaluated for a different number of receiver (Rx) points. The results showed that the parameter estimation accuracy is proportional to the number of receiver points. The distance and orientation errors of 45 m and 5 deg were achieved at 90th percentile with 40 Rx points. Furthermore, the prediction performance of the effective isotropic radiated power (EIRP) was decent, albeit a slight underestimation of the beamwidth.

The Small UWB Monopole Antenna with Stable Omnidirectional Radiation Pattern

Ultra Wideband (UWB) technology is an unmodulated wireless digital communication system that uses an extremely short duration pulse to transmit information bit. Because of this pulse, the UWB system needs a very wide bandwidth. Federal Communication Commission (FCC) has regulated the 3.1 – 10.6 GHz frequency spectrum for UWB. Since FCC released this frequency, many research in telecommunication have been done on UWB systems. One of them is a development of an Antenna that is suitable for UWB devices. UWB antenna characteristics require FCC band, omnidirectional radiation pattern, and compact size. In order to meet these needs, an antenna with a simple structure in the form of a monopole patch antenna with a similar patch size and ground width has been designed. The antenna is built on an FR4 – epoxy substrate material, with 4.4 dielectric constant and 1.6 mm thickness. The antenna feeding structure consists of two 100 Ω and 50 Ω lines with a wideband impedance matching scheme using tapered side and tapered transformers. The antenna design and optimization processes are conducted using electromagnetic simulation software, and measurements are carried out in an anechoic chamber. Simulation and measurement results show good agreement, and the antenna can work at frequencies 3.5 - 11.3 GHz with a gain of 1.5 – 3.25 dBi and stable omnidirectional radiation patterns. The antenna has dimensions of 27 × 8 × 1.6 mm, which are smaller than the antenna reported in the last research and suitable to be applied on various UWB devices.

Formation of the enterprise's digital communications system: aspects of economic business security

The study revealed the relevance of the issue of forming the digital communications system of the enterprise in modern conditions of information globalization and digital transformation of socio-economic relations; the relationship between the formation and improvement of the digital communications system and the strengthening of the economic security of business is shown. The purpose of the research is to determine the ways and justify the means of building the digital communications system of the enterprise, taking into account the requirements for ensuring the economic security of business. It has been established that the enterprise's digital communications system consists of such elements as search systems (in the form of a software and hardware complex for conducting data searches on the Internet, their accumulation and processing, placement in their own databases and sources of access to them, search queries), communication tools (with the use of which "communication" is carried out), digital technologies (methods of hosting and further dissemination of information) and digital communications in the global digital space, including semantic webs. The composition and structure of the elements of the enterprise's digital communications system have been determined. The parameters of the digital communication process management system of enterprises were built, and the goals and objectives of such work were defined. The conceptual sequence of the formation and use of the enterprise's digital communications system has been developed and substantiated. The directions of formation and immediate advantages, as well as risks and threats of the impact of the formation (improvement) of the digital communications system on the economic security of the enterprise are identified. The applied value of the research results is in the development of methodological and applied support for the management of the processes of formation (improvement) of the digital communications system at the business entity, as well as in the identification of risks and threats of digitalization to the economic security of the enterprise. The scientific novelty of the research results lies in the identification of both advantages (strengths), as well as risks and threats to the economic security of the enterprise by resource-functional components of economic security. Keywords: digital communications; digital system; economic security of business; economy and enterprise management; digital transformation; digitalization of business relations.

EXK-SC: A Semantic Communication Model Based on Information Framework Expansion and Knowledge Collision.

Semantic communication is not focused on improving the accuracy of transmitted symbols, but is concerned with expressing the expected meaning that the symbol sequence exactly carries. However, the measurement of semantic messages and their corresponding codebook generation are still open issues. Expansion, which integrates simple things into a complex system and even generates intelligence, is truly consistent with the evolution of the human language system. We apply this idea to the semantic communication system, quantifying semantic transmission by symbol sequences and investigating the semantic information system in a similar way as Shannon's method for digital communication systems. This work is the first to discuss semantic expansion and knowledge collision in the semantic information framework. Some important theoretical results are presented, including the relationship between semantic expansion and the transmission information rate. We believe such a semantic information framework may provide a new paradigm for semantic communications, and semantic expansion and knowledge collision will be the cornerstone of semantic information theory.

Fabrication and optimization of bi-quad antenna and energy-efficient balanced RF power amplifier for 5G-LTE multi-carrier applications

Wireless technology is presently one of the most actively researched fields of digital communication systems. Wireless communication technologies are insufficient without an understanding of antenna design and operation. A wide range of radio frequency equipment, including microwave antennas, microwave ovens, cordless telephones, and medical devices, utilize the 2.4 GHz band. In this article, a parabolic mesh dish was used to build and improve a bi-quad antenna with a central working frequency of 2.445 GHz. The bi-quad antenna was put in a parabolic mesh dish to optimize wave propagation. The findings show that the antenna obtained a signal strength range of 70% to 80%, increasing the directivity of WLAN coverage. The bi-quad antenna feed was placed in the center of a mesh dish, which assists in focusing radio waves onto the antenna. The bi-quad antenna outperformed the omnidirectional antenna, which had a signal strength of 56%. The results of each antenna test were separately simulated in MATLAB. The combined impact of bi-quad and parabolic was then duplicated using mathematical models, resulting in a unique waveform propagation pattern known as para-quad, which improved performance. A balanced RF power amplifier was conceived and built in this study. A 2.620 - 2.690GHz frequency range on a large signal Si-LDMOS transistor model achieves 53% PAE, 41dBm power output, and 14 dB gain at the P1dB saturation point.

The Comparison of BCH Decoding Methods and the Parameters Affecting the BCH Code Performance

In the communication field, channel coding was proposed to increase the data transmission rate and the transmitted data’s reliability. Error correction is an essential part of channel coding to improve data reliability. The Bose-Chaudhuri-Hocquenghem (BCH) code is one of the most efficient error-correcting codes. In this paper, a BCH coding method, and several methods to implement BCH decoding are introduced, and these decoding methods are compared with each other. Based on the principles of BCH codes, this study addresses two factors that may impact the performance of BCH codes, the redundancy bit length, and the minimum distance, as well as the relationship between them. This paper composes four flow charts and investigates the redundant bit lengths and minimum distances that may affect the performance of BCH codes during transmission. This paper is potentially beneficial for more extensive applications of BCH codes such as magnetic, optical storage systems, and new generations’ digital communication systems.

Advancing the Security of LDACS

The “Single European Sky” air traffic management master plan foresees the introduction of several modern digital data links for aeronautical communications. The candidate for long-range continental communications is the L-band Digital Aeronautical Communications System (LDACS). LDACS is a cellular, ground-based digital communications system for flight guidance and communications related to safety and regularity of flight. Hence, the aeronautical standards, imposed by the International Civil Aviation Organization (ICAO), for cybersecurity of the link and network layer, apply. In previous works, threat-and risk analyses of LDACS were conducted, a draft for an LDACS cybersecurity architecture introduced, algorithms proposed, and the security of a Mutual Authentication and Key Establishment (MAKE) procedure of LDACS formally verified. However, options for cipher-suites and certificate management for LDACS were missing. Also, previous works hardly discussed the topic of post-quantum security for LDACS. This paper proposes a cell-attachment procedure, which establishes a secure LDACS communication channel between an aircraft and corresponding ground-station upon cell-entry of the aircraft. Via the design of a hybrid LDACS Public Key Infrastructure (PKI), the choice of a pre-or post-quantum Security Level (SL) is up to the communications participants. With that, this work introduces a full LDACS cell-attachment protocol based on a PKI, certificates, certificate revocation and cipher-suites including pre-and post-quantum options. Evaluations in the symbolic model show the procedure to fulfill LDACS security requirements and a communications performance evaluation demonstrates feasibility, matching requirements imposed by regulatory documents.

MIND: Maximum Mutual Information Based Neural Decoder

We are assisting at a growing interest in the development of learning architectures with application to digital communication systems. Herein, we consider the detection/decoding problem. We aim at developing an optimal neural architecture for such a task. The definition of the optimal criterion is a fundamental step. We propose to use the mutual information (MI) of the channel input-output signal pair, which yields to the minimization of the a-posteriori information of the transmitted codeword given the communication channel output observation. The computation of the a-posteriori information is a formidable task, and for the majority of channels it is unknown. Therefore, it has to be learned. For such an objective, we propose a novel neural estimator based on a discriminative formulation. This leads to the derivation of the mutual information neural decoder (MIND). The developed neural architecture is capable not only to solve the decoding problem in unknown channels, but also to return an estimate of the average MI achieved with the coding scheme, as well as the decoding error probability. Several numerical results are reported and compared with maximum a-posteriori and maximum likelihood decoding strategies.

Design and Improvement of Digital Communication System Based on EDA Platform

The design of digital circuit systems based on EDA tools can greatly improve design efficiency. In this paper, a multi-mode communication signal modulation and demodulation system are designed with FPGA as the hardware carrier. Furthermore, this paper puts forward a teaching and experimental scheme of communication circuits, that is, using the EDA platform to realize different modulation and demodulation modes. The advantage of this scheme is that it can not only be realized in hardware, but also can analyze the performance accurately and that the waveform is intuitive. This scheme can make students feel the advantages of EDA Technology in complex logic circuit design. Students can understand new communication modes deeply by using EDA technology.