This article deals with the generating of pseudo-random Gordon-Mills-Welch sequences with good autocorrelation properties for use in communication and data transmission systems, as spectrum-expanding sequences, scramb...
This article deals with the generating of pseudo-random Gordon-Mills-Welch sequences with good autocorrelation properties for use in communication and data transmission systems, as spectrum-expanding sequences, scrambling and synchronization functions. Nowadays, there is a significant issue of pure detecting of signals in various types of radio channel. The proper solution of this issue provides new opportunities in the future research. The most important aim of usage of pseudo-random sequences is the reducing of influence of negative effects of channel and maximizing the probability of detecting the low-rate signal because of the unique form of autocorrelation function. Due to this feature, they are commonly used in the area of radars. The main goal of the article is to find out the exact types of Gordon-Mills-Welch sequences with suitable autocorrelation properties.
This article discusses the main features and characteristics of frameworks that allow creating cross-platform software for various mobile operating systems. The purpose of the work is to consider the most popular fram...
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This article discusses the main features and characteristics of frameworks that allow creating cross-platform software for various mobile operating systems. The purpose of the work is to consider the most popular frameworks for cross-platform mobile development, their functionality, to determine the specifics of their use, to identify their advantages and disadvantages, and to provide recommendations for choosing a framework for a number of application requirements. The subject of the research is software tools for developing cross-platform mobile applications. Popular frameworks such as Ionic, Flutter, ReactNative, and Xamarin are considered. The methodological basis of the work is the method of theoretical analysis and the descriptive method, the method of generalization and the comparative method.
The integration of a satellite network into a 5G mobile communication network is considered in order to provide users with broadcast multimedia content, where satellites can significantly expand coverage. The analysis...
The integration of a satellite network into a 5G mobile communication network is considered in order to provide users with broadcast multimedia content, where satellites can significantly expand coverage. The analysis of architecture options for such a network combining unicast technology with multiuser data transmission technology is carried out. This article explores the possibilities of using satellite broadcasting as an element of the delivery of broadcast multimedia content in 5G mobile communication systems. It is shown that such a combined network becomes capable of ensuring the quality of services, preventing congestion problems and increasing economic efficiency. It is proposed to use the VECTOR-2019 monitoring software and hardware complex for the study of 5G networks.
The aspects of mathematical modeling of the dynamics of complex processes in complex onboardsystems are considered. The structural connections between the elements of modeled systems and their dynamics are formalized...
The aspects of mathematical modeling of the dynamics of complex processes in complex onboardsystems are considered. The structural connections between the elements of modeled systems and their dynamics are formalized using a system of differential equations. Qualitative analysis of the synthesized model allowed establishing new non-local conditions for stable functioning of modeled combined onboardsystems. The results obtained make it possible to expand the working areas of technical devices and the devices included in onboardsystems.
The article is devoted to the development of signal-code structures (SCC) for low-energy broadband radio links. The SCC is based on multi-frequency signals with a continuous phase (M-Cpfsk) and non-binary error-correc...
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The article is devoted to the development of signal-code structures (SCC) for low-energy broadband radio links. The SCC is based on multi-frequency signals with a continuous phase (M-Cpfsk) and non-binary error-correcting codes (Non-binary low-density parity-check and turbo-like). An analysis is made of signal-code structures for bands up to 10 MHz with different parameters. These signal-code structures can be used for command-telemetry radio links from unmanned aerial vehicle (UAVs).
In the era of development of telecommunication technologies, triple-play services via IP networks in real time are of considerable interest both for operators of transport and on-boardsystems, and for consumers of se...
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In the era of development of telecommunication technologies, triple-play services via IP networks in real time are of considerable interest both for operators of transport and on-boardsystems, and for consumers of services. One of the characteristic features of real–time applications is their sensitivity to delays and data packet losses. Even small packet transmission failures can lead to a significant decrease in the quality of audio and video programs. All this imposes additional requirements on operators of transport and on-boardsystems delivering audio and video streams to content providers, which should be taken into account in their SLA agreements. The article discusses the requirements for IP network operators to deliver audio and video streams with proper quality, and provides an approach to evaluating the operator's performance when switching to SLA work.
One of recent advances in innovation computer technologies is widely using of on-board computing complexes. The major part of the on-board computing complex is the on-board information and computing network. Its main ...
One of recent advances in innovation computer technologies is widely using of on-board computing complexes. The major part of the on-board computing complex is the on-board information and computing network. Its main purpose is to ensure the reliable operation of on-board equipment. To design an on-board information and computer network, it is necessary to develop its mathematical model at the first stage. At the same time, most of the available models imply the working of network users with a “simple dialogue mode”, i.e. do not take into account the real technology of their work. However, it is possible to identify typical tasks solved by each of the users of the network, and describe in detail their working technology. Detailed consideration of network user's operation technology and its inclusion in the model can have a significant impact on its probabilistic and temporal characteristics. We consider some examples of such models by using closed queueing networks.
Network modernization using software-defined networks (SDN) technology and network functions virtualization (NFV) involves the use of a unified physical infrastructure, based on which various applications that impleme...
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ISBN:
(纸本)9781665415484;9781665446983
Network modernization using software-defined networks (SDN) technology and network functions virtualization (NFV) involves the use of a unified physical infrastructure, based on which various applications that implement all possible network functions operate. The explosive growth of mobile devices and content, as well as virtualization and the emergence of cloud services, is forcing the network industry to rethink traditional architectures. In networks with SDN architecture, the network industry is actively developing OpenFlow Protocol to provide communication between the control layer (SDN controllers) and data transfer devices (SDN switches). This article offers possibilities for modernization optical networks using various options for implementing SDN/NFV technologies.
Modelling of multipath signal propagation at 1.9 MHz has been carried out for different locations of reradiating objects relative to the transmitting antenna. Objects in the form of a vertical rod, a mast, a flat...
Modelling of multipath signal propagation at 1.9 MHz has been carried out for different locations of reradiating objects relative to the transmitting antenna. Objects in the form of a vertical rod, a mast, a flat screen and towers of various shapes are considered. It has been shown that distortions of the phase radiation pattern of more than 10 degrees can appear at distances between the reflecting object and the antenna up to 500 m or more. The object height and shape are of great importance.
Currently, most of the technical solutions for wireless communications and navigation systems prototyping and validation in academic and scientific community employ Software Defined Radio (SDR) technology. However, wi...
Currently, most of the technical solutions for wireless communications and navigation systems prototyping and validation in academic and scientific community employ Software Defined Radio (SDR) technology. However, wider utilizing of popular and well proven SDR platforms, such as USRP (Universal Software Radio Peripheral), LimeSDR and AD-FMCOMMS boards, is still difficult due to high cost and low availability. One of the solutions to popularize and make SDR wireless communication technology design more accessible for academic and scientific community is the emerging low-cost SDR-platform LibreSDR. Current work is devoted to experimental validation of LTE compliant transmission and reception of reference signals on physical layer, using LibreSDR board. The results of the experimental validation prove the potential of relatively low-cost LibreSDR utilization for wireless communications and navigation systems prototyping with the same performance, as well known USRP boards, among young scientists and students during their education and research in the academic and scientific community.
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