Quasi-orthogonal Hadamard matrices and Mersenne matrices with two and three values of the elements, used in digital data processing, are considered, as well as the basis of error-correcting codes and algorithms for transforming orthogonal images. Attention is paid to the structures of cyclic matrices with symmetries and antisymmetries. The connection between symmetry and antisymmetry of structures of cyclic Hadamard and Mersenne matrices on a orders equal to prime numbers, products of close primes, composite numbers, powers of a prime number is shown. Separately, orders equal to the degrees of the prime number 2 are distinguished, both the orders of Hadamard matrices and the basis of the composite orders of Mersenne matrices of block structures with two element values. It is shown that symmetric Hadamard matrices of cyclic and bicyclic structures, according to the extended Riser boundary, do not exist on orders above 32. Mersenne matrices of composite orders belonging to the sequence of Mersenne numbers 2k ‒ 1 nested in the sequence of orders of the main family of Mersenne matrices 4t ‒ 1 exist in a symmetric and antisymmetric form. For orders equal to the powers of a prime number, Mersenne matrices exist in the form of block-diagonal constructions with three element values. The value of prime power determines the number of blocks along the diagonal of the matrix on which the elements with the third value are located. The cyclic blocks are symmetrical and antisymmetric.

The article is dedicated to direct sequence spread spectrum signals acquisition. Communication channels that use direct sequence spread spectrum signals are characterized by significant delay and carrier frequency shift as a rule. That’s why the acquisition is most significant problem in receive equipment design. Suggested approach to acquisition problem base on the Fast Fourier Transform and discussed modeling suggested algorithm’s results.

An optical fiber with several unrelated cores inside a common clad (multi-core fiber) is used to increase the capacity of linear paths of communication systems. The number of cores in one fiber is limited by mutual influences between them, to reduce which various design solutions are used. The aim of the work is to compare various multicore fibers and identify structures that allow placing the largest number of cores in a common shell with a standard diameter of 125 microns.

In the first part of this paper, modeling of single-mode fibers with cores isolated by additional solid shells is carried out. As a result of modeling, the characteristics of the fundamental modes of the cores of each fiber are calculated – the distribution of the electric field strength, chromatic dispersion and the diameter of the field of the fundamental mode, a technique is proposed and an assessment of mutual influences is carried out, the maximum possible number of cores is determined. It is shown that the insulating clad reduces mutual influences and allows increasing the number of cores by reducing the distance between them.

The article discusses the method of forming a virtual antenna array based on magnetic dipoles. To test the effectiveness of the formation of a virtual antenna array, a simulation of an unmanned aerial vehicle with a directionfinding complex of four vector antenna elements was carried out. To perform direction finding, two methods are considered ‒ based on the electric field and magnetic. On the basis of the study, it was found that the use of direction finding based on magnetic dipoles can significantly improve the stability and accuracy of the bearing for both linear and elliptical electromagnetic waves. The article presents the main mathematical expressions that are used to determine the characteristics of the direction finding, as well as the dependence of the bearings in the studied frequency range.

The article is devoted to the collection and generalization of automatic identification system (AIS) data on the movement of ships, both on inland waterways and in coastal marine areas. The list of information necessary for the further carrying out of researches on the organization of movement is defined. Attention is paid to the peculiarities of obtaining data from technical means of communication and open online resources. The approach to statistical data accumulation from AIS receiver using Raspberry Pi single-board microcomputer has been offered. The application, which reads data from the serial port and transfers them to the library and then to the PostgreSQL database management system server, is implemented. It is concluded that the proposed approach is constructive and potentially effective.

Although low-density parity-check (LDPC) codes in modern communication standards have been extensively studied over a memoryless channel, their burst error correction capacity in channels with memory has yet to be thoroughly analyzed. The conventional approach to transmission in channels with memory uses interleaving within a buffer of several codewords. However, such an approach reduces the efficiency of the redundancy embedded by the error-correcting code. It is known from information theory that considering channel memory during decoding allows the transmission rate to be increased. An evaluation of the decoding error probability of different types of low-density parity-check codes in channels with memory is presented along with estimates of minimum distance and burst error correction capability for the considered codes. The decoding error probability is estimated for conventional decoding with deinterleaving and decoding taking channel memory into account. The decoding error probability is estimated for several parameters of a channel with memory and different buffer lengths. The obtained results reveal the absence of the unique decoding approach for all parameters of the channel with memory. The best decoding error probability is determined by the degree of channel memory correlation.

The purpose of the article is to study and model certain aspects (methods, algorithms for processing applications) of introducing blockchain technology into individual elements of state information systems. To achieve this goal, the following issues are sequentially considered in the article: analysis of the technical capabilities of blockchain, analysis of algorithms for processing applications on the state portal, study of the technological features of deploying a blockchain network to improve the efficiency of service provision, development of analytical relationships for studying the dependence of processing time, development of a simulation model for research processing time probabilistic characteristics. The article proposes a model for the application of blockchain technology in public information systems, for example, on the portal of public services, taking into account the large number of authorities involved in the process.  

The article considers the methodology for dynamic analysis of the cognitive model for assessing customer experience in the context of communication providers. The relevance of the study is due to the need for telecom operators to have a decision support system that allows analyzing dependence of customer experience on the efficiency of the company's operating environment, as well as emulating customer experience management scenarios in the context of the main sales and service processes. The objective of the study is to formalize the methodology of dynamic analysis of the model for assessing the integral customer experience that is based on fuzzy cognitive maps of the hierarchical structure. In particular, the mechanics of changing target factors (i.e., customer experience indicators) when perturbing control factors (i.e., operational performance indicators that affect customer experience) are investigated.

Flying Fog Mobile Edge Computing can play a pivotal part in the field of smart agriculture. Moreover, is an ideal choice for the significant features it enjoys such as its capability of functioning in remote locations, its wide coverage of areas, sufficient bandwidth, as well as its ability of dealing with connectivity issues. Hence, it is essential for smart agriculture provided with IoT devices to utilize offloading data in a real time and execution the satisfactory steps for a certain circumstance by using flying fog mobile edge computing. Flying Fog Mobile Edge Computing is a good choice to treat connectivity issues. In this paper, proposed a cooperation paradigm of UAVs and IoT devices towards smart agriculture for offloading and executing the computation tasks on-behalf IoT nodes by using dynamic programming algorithm and get satisfactory solution for constrained optimization problem and achieving minimize delay to accomplish tasks.

Autonomous vehicle (AV) is one of the most new use cases and a technology for fifth-generation (5G) and next-generation mobile networks in numerous applications., the use of AVs has exponentially worldwide due to the rapidly growing awareness and use of artificial intelligence (AI) methods in various fields. Predicting data flows is essential for AVs to improve data transmission and decrease delays through more efficient use of appropriate capabilities, monitoring, management, and control of the traffic system. This paper proposes a deep learning approach (DL) with the bidirectional long-short-term memory model (BI-LSTM) for predicting the traffic rates of AVs with multi-cloud services. In terms of prediction accuracy, a comparison is conducted between the BI-LSTM and the unidirectional LSTM based on the number of batch sizes used. The prediction accuracy is computed using the root mean square error (RMSE), mean absolute percentage error (MAPE), coefficient of determination (R²), and processing time. The results show that the prediction accuracy with BI-LSTM outperforms the LSTM model. Besides, the prediction accuracy using 8 batch sizes outperforms the competitors and offers outstanding performance.

The article describes a random access channel optimization technique based on the choice of roots for constructing random access preambles, the detection probability of which is higher than the roots selected in the classical way according. The results of simulation modeling are presented for the entire set of preambles 839 samples long. It is shown that with an increase in the number of simultaneously transmitted preambles, the spread of possible values of the correlation coefficient increases, which directly affects the success of detection. The conclusion is made about the possibility of optimizing the characteristics of the random access channel, both in terms of the configuration of the random access channel resources and based on the rational choice of the roots of the signal-forming preambles.

The article proposes a method for determining the composition of protocols used in IPsec communication channel, based on the regularities of the chronology and the lengths of encrypted load packets. The characteristic informative features of the protocols are considered. An algorithm is given to obtain the length values of ESP packets containing arbitrary user data for common modes of IPsec tunnel operation.

The paper considers the isogeny-based cryptographically enforced data access control scheme CSIDH-HRBAC for untrusted cloud. CSIDH-HRBAC is based on a role-based access control model with support for a role hierarchy system. The proposed scheme implies the presence of a trusted party that manages cryptographic keys associated with users, roles, files. The basic procedures for gaining access to data, revoking access rights, adding new entities and updating parameters are given. Typical scenarios of attacks on the proposed scheme are considered, including role substitution, collusion by participants to compute the parent role key, attempt to access data after role revocation from user. To evaluate the performance of cryptographic operations, the simulation of the basic procedures was performed. The advantages and limitations of the CSIDH-HRBAC scheme are discussed. In particular, the need for protection against threats from the administrator, the prospect of using lattice-based post-quantum cryptographic primitives is noted.