The article considers an approach to the modification of manipulative impulse sequences based on Barker codes. It is proposed to change the structure of the encoded pulses by the duration of the elementary message, taking into account the change in the duty cycle of their repetition while maintaining the total average energy. Numerical relations are obtained that determine the spectral and temporal parameters for a seven-element pulse sequence, with an increase in the pulse repetition rate by two and three times. Numerical values are calculated that determine the ratio of the duration of the peaks of the cross-correlation functions between the modified and canonical forms of pulse sequences. Reasonable estimates are presented that characterize the increase in the resolution of the peaks of the cross-correlation functions by 4.43 times in the transition to the proposed modified structure of the pulse sequence.

The article describes the results of a flight experiment on the use of a public mobile communication network, conducted in St. Petersburg and its suburbs. The numerical values are given for the signal quality parameters: RSSI, RSRP, RSRQ, SNR and the average data transfer rate from the UAV and to the UAV. It is shown that interRAT handover significantly affects the urban area, which is associated with a high density of base stations. It is concluded that it is possible to transmit video traffic from a UAV for infrastructure monitoring with requirements for a data transfer rate of 1‒1.5 Mbps.

The article considers optimum noncoherent demodulator scheme. The symbol synchronization is key problem of demodulator’s performance. It is offered the resampler symbol synchronization sсhem. Modeling demodulator algorithm results is shown. The modeling results let to propose the optimum noncoherent demodulator scheme. It is shown that the demodulator provided near to ideal noncoherent performance. Based on the results presented in the paper, receivers of various broadband signals can be constructed.

Modern diagnostic systems used to control railway infrastructure are equipped with technical vision systems. In addition to video recording, these systems perform recognition tasks and measure parameters necessary for the automation of technological processes. One of the existing tasks is to measure the velocity of long objects. Measuring velocity is necessary for slowing down a carriage on a gravity yard, for the formation of an image of extended objects (separate wagons or convoys) that cannot fit into the frame as a whole (the image is formed from fragments of different frames). The article describes the procedure of verifying fragments of images used to measure the velocity of extended objects, which increases noise immunity. The verification procedure improved the existing algorithm based on comparing two adjacent frames to calculate the speed of motion, thus increasing the reliability of measurements.

The article presents the analysis of characteristics of algorithms of signal precoding in a multi-antenna system with many users (MU-MIMO). This paper presents the numerical evaluation of the multiuser MIMO beamforming algorithms ZF and DFT codebook based on a QUADRIGA channel model, taking into account the real conditions of signal propagation. The generated channels are used to calculate SINR and the spectral efficiency values of each user using the conventional ZF and DFT beamforming codebook. The eigenvalues of the MIMO channel are important in evaluating the MU-MIMO transmission performance characteristics, such as the spectral efficiency of a precoded system. The obtained performance of MU-MIMO ZF and DFT codebook-based beamforming in spatially correlated channels are compared based on the empirical cumulative density function of the sum rate of multiple users. Spatial correlation degrades capacity performance, and in the channels, the DFT precoder has a more robust performance and outperforms the ZF precoder in spectral efficiency. Obtained results can be used by the algorithm evaluation in the system-level simulations.

The paper presents the results of a numerical simulation of the flight conditions of a helicopter-type aircraft with a change in variables that affect flight safety. A comparative analysis was conducted assessing the threat of an aviation accident, considering the influence of the psychophysical state of the crew. Particular attention is paid to the modelling of the decision support system for countering the threat of an accident, based on the aircraft’s flight conditions and the knowledge base of the Flight Safety Management System. The obtained results in the course of this work make it possible to evaluate the effectiveness and efficiency of the methods for assessing and parrying the threat of an aviation accident. The proposed methods can be implemented with the software and hardware of the on-board flight safety systems of the aircraft

The use of motion vectors for identifying video sequences has been well studied (in the framework of research on the topic CBCD – Content-Based Copy Detection ‒ detecting copies of videos based on content analysis). This makes it possible to check the similarity of two video fragments or search for a fragment in a larger video sequence. Existing and well-known methods for forming identification datasets typically use complete video stream decoding. The authors suggested using the motion vectors of a compressed video stream, which reduces the computational costs for identifying video sequences and uses simplified algorithms to generate identification data. Unlike the previously proposed methods, which implement either modified video codecs or obsolete ones, the authors propose using data formed by compression codecs that are used in the most common video hosting platforms (Youtube, Vimeo, etc.) The possibility of forming an automated system of comparing video sequences, along with its possibilities and limitations, will be studied in the following works.

With the increasing demands for mobility and guaranteed quality, new technologies with new capabilities, such as 4G and 5G networks, have appeared to meet the needs of users. Indeed, 4G networks are constantly striving to improve the services offered and guarantee a certain level of quality of service (QoS). The 5G standard promises ultrafast speeds and an end to congestion in mobile networks. This technology is expected to revolutionize mobile networks and create new economic opportunities. In this context, the purpose of this article is a detailed comparison of 4G and 5G technologies. Thus, we outline the various characteristics of 4G systems, that is, their contribution and their behavior in terms of maintaining QoS. We will also evaluate the efficiency of virtualization and mobile edge computing in modern networks.

The article is devoted to the analysis of network resource management methods in the SDN network. In the interests of this, a review of the scientific works was carried out by Russian and foreign authors to identify the solutions used in them, as well as their advantages and disadvantages. The methods covered in scientific articles are systematized according to the following criteria: year of publication, level of applicability of the method (physical, logical, network), availability of a mathematical model, load balancing mode relative to the time of the incident, range of tasks to be solved, degree of research (theoretical, experimental, practical). Based on the analysis of the results of the review, it was concluded that the solutions were unsatisfactory, as well as the need to consider the new IBN technology, covering a wide range of applications and working preventively at all SDN levels.

The article considers individual factors of loss growth in polymer planar optical waveguides, which are included in the composition of optical-electronic buses, introduced in perspective new generation printing boards. The article proposes several approaches to reducing losses in optical radiation, which include losses at the end of the optical waveguide and the light transition to the input/output element of the optoelectronic bus of the printed circuit board. According to the results of modelling the modal structure of a polymer planar optical waveguide, made from a polymer material, polydimethylsiloxane (PDMS), in the software environment of Comsol Multiphysics, the dimensions of the core optical waveguide are determined, providing a single-mode structure of an optical waveguide. A measuring stand was developed and assembled for calculating the transmission losses in polymer planar optical waveguides of the optoelectronic bus of a printed circuit board, which meets the requirements of IEC 62596-2: 2017. The minimum measured loss in the manufactured polymer planar optical waveguides was 20 dB, which corresponds to foreign analogues of the optical-electronic bus of the printed circuit board.

The paper proposes numerical methods to calculate the data transfer rate over a communication channel with real signals in the presence of a mixture of Gaussian and non-Gaussian correlated noise. This paper considers the transmission of discrete and continuous messages. The estimate of the data transmission rate given by the proposed methods is much more accurate than the estimation given by the Shannon limit. The proposed methods can be used for the information-theoretical analysis of the wide range of systems: systems of digital and analogous communication, radiolocation and radio navigation.