Two-Time Procedure for Calculation of Carrier Frequency of Phasomodulated in Communication Systems

The use in radio communication systems of phase modulation of a signal intended for the transmission of useful information in a continuous mode creates the problem of frequency uncertainty of the received signal by frequency.In practice, it is not possible to implement frequency estimation in the conditions of chat uncertainty of the signal in the channel with low energy of the signal received in the continuous mode. Therefore, the estimation of the carrier frequency offset of the signal received relative to the nominal value is carried out before other synchronization procedures are included, namely: phase synchronization and clock synchronization. The paper generalizes the procedure and forms a two-step procedure for calculating the carrier frequency of the phase-modulated signal of a radio communication system for data transmission in a continuous mode, taking into account the condition of uncertainty of all signal parameters. Achieving the minimum observation interval in the given order of calculation of the carrier frequency is ensured by the use of the fast Fourier transform function. In order to analyze the effectiveness of this procedure, the process of estimating the carrier frequency of the phase-modulated signal of the radio communication system during data transmission in continuous mode and functional dependences of the maximum frequency in the signal spectrum and the minimum variance of carrier frequency estimation. This procedure allows a two-stage assessment of the carrier frequency according to the rule of maximum likelihood, taking into account the condition of uncertainty of all parameters of the signal received by the satellite communication system in a continuous mode with a minimum observation interval. Achieving the minimum observation interval in the given order of carrier frequency estimation is ensured by using the fast Fourier transform function and two estimation steps. The analysis of the efficiency of the estimation of the specified order was carried out on the basis of comparison of a ratio of the received minimum variance of an estimation of a carrier frequency and theoretically possible border of the minimum variance.

On the assessment of the reliability of the train radio communication channel

The research purposeis to develop an approach to assessing the reliability of a train radio communication channel based on the representation of a radio communication network in the form of a model that includes both traditional elements (various types of equipment, a wire channel) and a radio channel, which is proposed to be described by the availability of radio coverage, which varies depending on the location of the mobile subscriber. In the research methods of the theory of reliability, and, in particular, the assessment of the availability factor of the elements of the radio communication system and communication channels, dynamically changing during the movement of the mobile radio station. In addition, to assess the energy of radio channels, the theory of radio wave propagation was applied, including on the basis of industry recommendations for calculating radio communication networks of JSC Russian Railways. As result of the research, a method was proposed for assessing the dependence of the reliability of a train radio communication channel (in terms of readiness) on the track coordinate. In this case, the radio communication channel dynamically changes the composition of the elements when the mobile subscriber moves along the railway section. Simultaneously, for each point of the section, the calculation formula is also dynamically changed, which makes it possible to find the value of the readiness of the communication channel. The proposed approach allows to identify the sections of technological radio communication networks that are weakest from the point of view of communication reliability and take this information into account when planning work to improve the reliability of communication networks.

Design of Minkowski Array Microstrip Fractal Antenna at 3.5 GHz Frequency for 5G Communication System

Technological developments in the field of telecommunications are experiencing rapid progress, especially the presence of 5G technology as a fifth generation cellular communication system that has many advantages at the World Radiocommunication Conference (WRC) in 2015, 5G candidate frequency bands below 6 GHz have been widely discussed, and the range the following frequencies have been suggested: 470–694, 1427–1518, 3300–3800, and 4500–4990 MHz. One of recommendation of resonant frequency is 3.5 GHz, as it is acceptable in most countries. Therefore, a reliable communication network is needed, especially in the 3.5 GHz frequency band for fifth generation applications. Antena is one of the important communication components in radio communication system. Mikrostrip Antena is a type of Antena that is currently growing because it has the advantage of having a light weight and low profile. This paper proposed development of mikrostrip Antena using the fractal method, increase the gain using the Array method, and achieve the target return loss ≤ -10 dB, VSWR ≤ 2, and gain ≥ 5 dB at frequency of 3.5 GHz for 5G communication sytsem. Proposed Antena is designed using a duroid R5880 substrate with a dielectric constant value of 2.2, a dielectric loss (tan loss) of 0.0009 and a substrate thickness (h) of 1.57 mm. This study resulted in a reduction in Antena dimensions until 53.76% with return loss of -42.48 dB, VSWR 1.02, and a gain of 8.46 dB. The results obtained in this design meet the specifications of the predetermined targets.

EMC assassement criteria and interference protection for basic radio services in accordance with ITU-R recommendations

The effect of unwanted energy due to one or a combination of several desired and unwanted emissions upon reception in a radio communication system results in performance degradation, misinterpretation or loss of information. Multiple sources of interference may affect the receiver input: services of the same type or other operating in the same frequency band, services operating in adjacent frequency bands, sources generating continuous or short term interferences, fixed or mobile sources, etc. To prevent such interfering situations, a key element is the standardization of appropriate criteria for electromagnetic compatibility (EMC) and interference protection (IPC). The purpose of the studies and analyzes in this article is to systematize the criteria for electromagnetic compatibility for basic radio services based on the Publications of ITU-R. Criteria for four important areas of radio communications covering fixed, fixed satellite, broadcasting and mobile radio services are compared. Contributions are the categorization of the criteria according to the type of interfering signal and the results of the analyses, which show that the regulatory requirements and practical methods for interference protection and EMC for different radio services differ. Detailed criteria for predicting the probability of interference being standardized only for some radio services.

The improvement of method for the multi-criteria evaluation of the effectiveness of the control of the structure and parameters of interference protection of special-purpose radio communication systems

Military radio communication systems are the basis of special purpose control systems and the object of the enemy’s primary influence. Therefore, the issue of increasing the noise immunity of military radio communication systems is important and needs further research. Thus, the object of the research was chosen to be a military radio communication system. Maintaining a given level of noise immunity for military radio systems is one of the key issues in radio resource management, the effective management of which allows the use of the entire suitable frequency range for the transmission (reception) of electromagnetic energy by radio electronic devices. A number of works have been devoted to the ways search for increasing the noise immunity of military radio communication systems. One such way is to develop new (improve existing) approaches for assessing the effectiveness of military radio interference management. This work solves the problem of improving the method of multicriteria management effectiveness evaluation of the structure and parameters of the military radio systems noise protection. The scientific problem is solved by the devices of multicriteria estimation of the of noise protection level of the military radio communication system, graphic display of the executed and not executed tasks, the aggregation scheme of formation of the integrated estimation of noise protection. The research used scientific methods of analysis and synthesis, also the theory provisions of signal-code structures and the provisions of the complex technical systems theory. The peculiarity of the proposed improvement of the methodology is the multi-criteria assessment of the noise immunity level of the military radio communication system in the conditions of radio electronic conflict. The proposed technique allows: – to evaluate the effectiveness of noise protection management; – to substantiate the optimal configuration of the military radio communication system in solving the problems of noise protection management in the conditions of radio electronic conflict; – to identify the ways to increase noise immunity at the stage of operational management of the military radio communication system in the conditions of electronic conflict. The results of the research should be used in assessing the effectiveness of management of noise protection of military radio communication systems and determining the optimal structure and parameters of military radio systems.

Development of the method of structural-parametric synthesis of the subsystem of interference of special purpose radio communication systems

The object of research is the military radio communication system. One of the most problematic areas in the management of military radio resources is the interference of military radio systems and facilities. A number of works have been devoted to the research of ways to increase the noise immunity of military radio communication systems and facilities. However, the known works contain some results of research by scientists aimed at increasing the noise immunity of military radio systems and facilities and do not have a comprehensive approach. In this article, the problem of developing a method of structural-parametric synthesis of the noise protection subsystem of special purpose radio communication systems is solved. The scientific problem is solved by formalizing the problem of structural-parametric synthesis of the noise protection subsystem of military radio communication systems, starting with its mathematical description and synthesis of the quantitative and qualitative structure of the noise protection subsystem. In the course of the research, the authors used the main provisions of the queuing theory, the theory of automation, the theory of complex technical systems and general scientific methods of cognition, namely analysis and synthesis. The novelty of this technique is the synthesis of the structure of the military radio system and the parameters of the radio system in the context of electronic conflict. This technique is multi-criteria, in which the parameters are different in importance. The basis of this technique is the principle of nonlinear scheme of A. Voronin compromises. This technique allows to: – to synthesize the structure of the radio communication system in the conditions of electronic conflict; – to determine the optimal number of radio communication devices to ensure management tasks in the conditions of electronic conflict; – to substantiate a set of mechanisms to increase the noise immunity of the noise protection subsystem in the conditions of electronic conflict. The results of the research should be used at the stage of planning and operational management of the structure and parameters of military radio communication systems.

Aplikasi Monitoring Energi SHS Off-Grid Menggunakan Lora

The manner of efficiency and effective of power usage is the main objective in electricity consumption, one major steps to control the usage is by providing a monitoring to aim the power usage data and process it to information needed. Internet of Things benefit in power and electricity has involved sensors to work as data reader continuously. LoRa or well known as Long Range radio communication system work with chirp spread spectrum which work from 920 to 923 Mhz in Indonesia. This paper presents implementation of LoRa system to support the prototype of energy monitoring in Solar Home System off-grid