Military Wireless Research Articles

JamBIT: RL-based framework for disrupting adversarial information in battlefields

During battlefield operations, military radios (hereafter nodes) exchange information among various units using a mobile ad-hoc network (MANET) due to its infrastructure-less and self-healing capabilities. Adversarial cyberwarfare plays a crucial role in modern combat by disrupting communication between critical nodes (i.e., nodes mainly responsible for propagating important information) to gain dominance over the opposing side. However, determining critical nodes within a complex network is an NP-hard problem. This paper formulates a mathematical model to identify important links and their connected nodes, and presents JamBIT, a reinforcement learning-based framework with an encoder–decoder architecture, for efficiently detecting and jamming critical nodes. The encoder transforms network structures into embedding vectors, while the decoder assigns a score to the embedding vector with the highest reward. Our framework is trained and tested on custom-built MANET topologies using the Named Data Networking (NDN) protocol. JamBIT has been evaluated across various scales and weighting methods for both connected node and network dismantling problems. Our proposed method outperformed existing RL-based baselines, with a 24% performance gain for smaller topologies (50–100 nodes) and 8% for larger ones (400–500 nodes) in connected node problems, and a 7% gain for smaller topologies and 15% for larger ones in network dismantling problems.

Small-sized active phased array antenna for base stations of mobile radio networks in limited deployment conditions

Today, most telecommunications structures are oversaturated with antenna technology. There is a need to use high-rise buildings and facilities that are not equipped for communication. However, the use of such objects imposes a number of restrictions on the installation locations of antenna systems. Thus, the problem arises of developing an antenna system that makes it possible to achieve a circular radiation pattern using small-sized antennas. A model of a small-sized UHF AFAR has been developed. A distinctive feature of this AFAR is the use of a ring active phased antenna array with an electrically controlled radiation pattern as an antenna system. Such solutions have not been used in domestic antenna technology, including military radio communications. The antenna complex is proposed to be used for installation on mobile objects, as well as on the upper platforms of towers and masts to provide a circular radiation pattern in places where it is impossible to implement a ring antenna array around the perimeter of the object.

МАТЕМАТИЧНЕ МОДЕЛЮВАННЯ ПРОЦЕСІВ ФУНКЦІОНУВАННЯ АВТОМАТИЗОВАНИХ СИСТЕМ ВІЙСЬКОВОГО РАДІОЗВ’ЯЗКУ В УМОВАХ ЇХ ЗАХИСТУ ВІД РАДІОРОЗВІДКИ

The article reveals the basic theoretical provisions and the essence of the approach to modeling the processes of functioning of automated military radio communication systems in terms of their protection against radio reconnaissance. An algorithm for determining rational radio exchange routes with low intelligence availability in an automated military radio communication system is proposed, which is the basis for solving the problem of multi-path routing and takes into account, in addition to the known limitations, the restrictions on the permissible intelligence availability of information flow routes, which is essential for military radio communication. A mathematical model of the functioning of an automated military radio communication system has been developed, which for the first time: takes into account the process of its protection against radio reconnaissance by radio exchange along rational routes with low intelligence availability; is based on the tensor dependencies of the coefficients of intelligence availability of individual direct radio communication lines on the quality indicators of information exchange in the elementary basis of the structure of the automated military radio communication system with their subsequent transformation to tensor dependencies of the coefficients The proposed theoretical positions can be used in the creation of training complexes (training base) based on artificial intelligence in order to increase the efficiency of troop training.

Microstrip Patch Antenna Design at 10 GHz for X Band Applications

Microstrip patch antennas are used in satellite imaging systems, wireless communication equipment, military radios, GPS (Global Positioning System) and GSM (Global System for Mobile Communications) applications. Its advantages are its small size and light weight, thin structure, low power consumption, use in dual frequency applications, and patching in various geometric shapes. Developing technology has facilitated and accelerated the production of microstrip antennas. In this study, microstrip antenna design operating at 10 GHz frequency for X band applications has been made. X band is used for air traffic control, weather traffic control, vessel traffic control, defense tracking and vehicle speed detection, terrestrial communications and networking, space communications and amateur radio. HFSS program was used in antenna design. AWR program was used to find transmission line parameters. In addition, MATLAB program was used to calculate some parameters. First of all, information is given about the working principle of the antenna, the selected dielectric layer and the working frequency. Schematic drawings of the designed antenna were made from above and from the side. S11 reflection coefficient magnitude graphs are drawn below and above the operating frequency. The radiation pattern is drawn for the E-plane and H-plane at the operating frequency. 3-D (dimensional) plot of antenna gain at operating frequency is drawn. The simulations performed have shown that the designed antenna works successfully.

Advanced Military Radio Channels Monitoring System Based on Software Defined Radio Platform: Preliminary Analysis

Abstract The use of electromagnetic spectrum monitoring for military emissions is essential due to the mobility and diversity of military operations. A tactical communications system used in the military domain includes encrypted and unencrypted data, voice and video communications using wideband and narrowband waveforms. This research focuses on the development of a high capability monitoring system based on Software-Defined Radio (SDR) technology for monitoring military waveforms. The implemented system has been tested for its ability to detect both wideband military waveforms and narrowband frequency hopping waveforms. The proposed SDR-based system provides a cost-effective solution for military waveform monitoring that can be used for real-time monitoring and analysis of the electromagnetic spectrum.

Wideband to narrowband/dual band characteristics of monopole antenna using frequency selective surfaces

SummaryA monopole antenna having desirable transmission characteristics with high gain is proposed. The monopole antenna comprises 45° tilted square shaped patch and modified rectangular metallic ground plane on FR4 dielectric substrate. The proposed monopole antenna operates from 2.6 GHz to 9.7 GHz with maximum peak gain of 2.3 dBi. Now, a dual‐layer aperture‐type FSS is designed having a passband from 5.9 GHz to 9.2 GHz and incorporated with the proposed monopole antenna. Thus, the combination only covers the selective frequency band from 5.5 GHz to 8.7 GHz with a stable gain of around 5 dBi. Second, another FSS is designed, which has one stop‐band from 4.1 GHz to 5.4 GHz and two passbands on the both sides of this stop‐band. This combination does not work from 4.1 GHz to 5.5 GHz but covers dual band from 2.48 GHz to 3.3 GHz with a peak gain of 5 dBi and 5.5 GHz to 10 GHz with a peak gain of 5.5 dBi. Therefore, without modifying the antenna design, any tunable transmission band can be achieved by the proposed combination. The proposed antenna and FSS combination structure may be suitable for military wireless applications for its band selection characteristics.

Substantiation of technical characteristics of promising high-speed multi-band broadband military radio stations

The issue of improving the technical characteristics of promising high-speed multi-band broadband military radios is an important issue. It happens because of the increase in the number of devices of communication in information and telecommunication networks, as well as the growing requirements for the level of technical characteristics of these devices. Given the above, the object of the research is a promising high-speed multi-band broadband military radios. The subject of the research is the technical characteristics of promising high-speed multi-band broadband military radios. In the course of the research, classical methods of analysis and synthesis were used. The research analyzes global trends in the construction and development of wireless access networks, which allows concluding on the prospects of development (purchase) and implementation of high-speed multi-band broadband military radios for the Armed Forces of Ukraine. The results of the analysis of characteristics and parameters of high-speed multi-band broadband radio stations of the world's leading countries allow to determine the main features and requirements for promising radios, as well as to substantiate the use of high-speed radio stations in the Armed Forces of Ukraine. The conditions and factors influencing the possibilities of using promising broadband radio stations in the conditions of modern wars and armed conflicts are determined. The analysis allows to conclude that broadband radio access systems will be used to organize access to information resources in the information and telecommunications environments of network-centric and information wars.

A Modified SWB Hexagonal Fractal Spatial Diversity Antenna With High Isolation Using Meander Line Approach

This manuscript introduces a novel miniaturized super wideband (SWB) hexagonal fractal spatial diversity 2-element multiple-input-multiple-output (MIMO) antenna for broadband applications, as a compact wideband antenna is required for military radio and space communication devices. The designed antenna includes two hexagonal ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1^{st}$ </tex-math></inline-formula> modified Koch iteration) Koch fractal radiators with two linear tapered feedlines (TLTF) and a step tapered slotted ground plane (STSGP) that provides the broad impedance characteristic with miniaturized size in the operating band of 1.78-30 GHz. Moreover, the STSGP is also accountable for enabling the isolation ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S_{12/21}$ </tex-math></inline-formula> ) better than 10 dB. To further meet the isolation higher than 22 dB, a meander line is protruded from the ground plane while maintaining a 6 mm edge-to-edge distance between two antenna elements. Typically, the MIMO antenna with high isolation is beneficial for high-speed data transmission. The experimental outcomes represent that the proposed MIMO antenna is with the advantages of reasonably good diversity gain (nearly 10 dB), stable radiation patterns, high peak gain (almost 6.6 dBi), and moderate radiation efficiency (around 85%) across -10 dB impedance bandwidth. The total active reflection coefficient (TARC) and envelop correlation coefficient (ECC) are less than −25 dB and 0.1 respectively. Due to all these attributes, the proposed 2-element MIMO antenna array can be a potential candidate for military radio, spectrum sensing for cognitive radio, and space communication applications.

Increasing the anti-jammingness of mobile radio networks with adaptive beamforming.

MANET radio networks (mobile radio networks, MRN) are increasingly used for tactical military radio communications in recent years. Anti-jammingness of such radio networks can be much higher compared to conventional radio networks (with or without a repeater) due to the possibility of multiple relay of messages.A promising direction to increase the noise immunity of MRN at the physical level is the use of antenna arrays (AR) with the ability to control the direction of the main radiation, which allows to ensure maximum values of signal-to-interference ratio at the inputs of individual radio stations. At the same time, in order to ensure maximum noise immunity in such MRNs, it is necessary to take into account the peculiarities of the formation of directional diagrams of antennas of radio stations of the network, spatial coordinates of radio stations and jammers.The article analyzes the tasks that arise when implementing the technology of adaptive charting in MRN in the conditions of active electronic countermeasures, the main ones are the following: determination of the spatial coordinates of the own station, network correspondents and the jammer; calculation of the optimal angle of orientation of the main lobe of the antenna pattern when receiving a signal from neighboring correspondents, taking into account the mutual location of radio stations and the jammer; practical implementation of the exchange of coordinate information between radio stations.Taking into account and solving these tasks will ensure the effective implementation of routing protocols in the mobile radio network with the AR, and increase interference protection in both individual information areas and the radio network as a whole.

TNT: A Tactical Network Test Platform to Evaluate Military Systems Over Ever-Changing Scenarios

This paper addresses the challenge of testing military systems and applications over different communication scenarios with both network conditions and user data flows changing independently. We assume that systems developed to handle ever-changing communication scenarios are more likely to be reliable and robust during real military operations. Therefore, we propose the Tactical Network Test (TNT) platform to automate the evaluation of military systems and applications over real military radios using a reproducible test methodology. TNT has four main goals (i) the creation of QoS-constrained data flows; (ii) the execution of models to change network conditions; (iii) the automation of experiments to quantify the performance of military systems over ever-changing communication scenarios; and (iv) the monitoring of quantitative metrics and performing data analysis. Our platform was used to execute experiments in a VHF network by sending uniformly distributed data flows during seven different communication scenarios, either generated by a stochastic model or mobility models. The experimental results are used to discuss the military system’s performance by quantitative analysis using network metrics, and the test scenario characterization using mobility metrics.

Analysis of methods for increasing the efficiency of dynamic routing protocols in telecommunication networks with the possibility of self-organization

The object of research is the military radio communication system. Effective operation of routing protocols is possible only if there is reliable information about the network topology for network nodes, given that the mobility of individual nodes is insignificant in special purpose wireless networks. Because nodes in the network demonstrate the mobility property of the node groups. This paper solves the problem of the analysis (decomposition) of methods of protocols efficiency increase of dynamic routing in telecommunication networks with a possibility to self-organization. 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. This research analyzes various methods to increase the efficiency of dynamic routing protocols. Energy efficiency methods focus on three main components in energy management: battery management, transmission energy management and system energy management methods. Reliable multicast has become indispensable for the successful deployment of special purpose wireless networks, such as in tactical military operations and emergency operations. The results of the research will be useful in: – development of new routing algorithms; – substantiation of recommendations for improving the efficiency of the route selection process in networks with the possibility of self-organization; – analysis of the electronic situation during hostilities (operations); – while creating promising technologies to increase the efficiency of mobile radio networks. Areas of further research will focus on the development of a methodology for the operational management of interference protection of intelligent military radio communication systems.

Development of a simulation model for a special purpose mobile radio network capable of self-organization

The object of research is the military radio communication system. Effective operation of routing protocols is possible only if there is reliable information about the network topology for each of the network nodes. Construction of special purpose radio networks with the possibility of self-organization is possible only in the presence of adequate and reliable models of their work in different applications and the impact nature. It necessitates the development of new and adequate algorithms (methods, techniques) for modeling routing algorithms in special purpose radio networks with the possibility of self-organization. This work solves the problem of developing a simulation model of a mobile radio network for special purposes with the possibility of self-organization. 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. This simulation model was developed to assess the effectiveness and adequacy of the developed scientific and methodological apparatus for routing management in special purpose radio networks with the possibility of self-organization. The research results will be useful in: ‒ development of new routing algorithms; ‒ substantiation of recommendations for improving the efficiency of the route selection process in networks with the possibility of self-organization; ‒ analysis of the electronic situation during hostilities (operations); ‒ while creating promising technologies to increase the efficiency of mobile radio networks; ‒ assessment of adequacy, reliability, sensitivity of routing algorithms; ‒ development of new and improvement of existing simulation routing models. Areas of further research will focus on the development of a methodology for the operational management of interference protection of intelligent military radio communication systems.

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.

Analysis of mathematical models of mobility of communication systems of special purpose radio communication systems

The object of research is the military radio communication system. One of the problems in improving the effectiveness of military radio communication systems is the correct description of the movement process in them. Efficient routing protocols are only possible if reliable information on network topology for network nodes is available. Thus, with this information, packets can be forwarded correctly between the sender and the recipient. Given that the mobility of individual nodes is insignificant in special wireless networks, nodes in the network show the mobility properties of a group of nodes. This observation is directly related to the very existence of military wireless networks with the ability to organize themselves, that is, to support group cooperation and group activities. In this work the problem of analysis (decomposition) of the mobility models of military radio communication networks with the possibility of self-organization is solved. The classification of mobility patterns, the description of individual mobility models and the analysis of various aspects currently available, as well as those properties lacking in the attempt to simulate the movement of individual nodes, have been carried out. During the research, the analysis of random, semi-deterministic and deterministic models was carried out. The advantages and disadvantages of the above models have been identified. In the course of the research, the authors of the work used the main principles of the theory of mass service, the theory of automation, the theory of complex technical systems, as well as general scientific methods of knowledge, namely analysis and synthesis. The research results will be useful in: ‒ synthesis of mathematical models of node mobility; ‒ evaluation of the effectiveness of the science-based tool for assessing the mobility of nodes; ‒ validation of recommendations to improve the efficiency of mobile radio networks; ‒ analysis of the radio-electronic situation during the conduct of military operations (operations); ‒ creating advanced technologies to improve the efficiency of mobile radio networks.

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.

Justification of ways increasing the immunity of special purpose radio communications

The object of research is the military radio communication system. One of the most problematic areas in the military radio resources management is the interference of military radio systems and facilities. A number of works have been devoted to the study of ways to increase the noise immunity of military radio communication systems and facilities. However, the known works contain some research results by scientists, which are aimed at increasing the noise immunity of military radio communication systems and devices and do not have a comprehensive approach. This work solves the problem of substantiating ways to increase the noise immunity of military radio communication systems and facilities. The scientific problem is solved by substantiating the methodological principles of increasing the noise immunity of military radio communication systems in conditions of a priori uncertainty. During the research, the authors used the main provisions of the queuing theory, the theory of automation, the theory of complex technical systems, as well as general scientific methods of cognition, namely analysis and synthesis. The novelty is that in the course of work: – the purpose of functioning of the noise protection system of military radio communication systems is formulated; – indicators and criteria for increasing the noise immunity of military radio communication systems have been determined; – decomposition of the solution of this problem into problems depending on the signal and noise situation is carried out. An approach based on the hierarchical decomposition of the networks functional structure, the behavior of which is described by stochastic differential (or difference) equations of the high dimension state, into a number of interconnected but simpler functional structures is used for the functional description of military radio communication systems. The proposed approach to describe the behavior of military radio systems will allow to decompose the military radio system state and increase the efficiency of decision-making to adjust operating modes and parameters in real time. The results of the research should be used at the stage of parameters operational management and modes of the system operation.

Influence of Aircraft Power Electronics Processing on Backup VHF Radio Systems

The paper describes the influence of power electronics, energy processing, and emergency radio systems (ERS) immunity testing on onboard aircraft equipment and ground stations providing air traffic services. The implementation of next-generation power electronics introduces potential hazards for the safety and reliability of aircraft systems, especially the interferences from power electronics with high-power processing. The paper focuses on clearly identifying, experimentally verifying, and quantifiably measuring the effects of power electronics processing using switching modes versus the electromagnetic compatibility (EMC) of emergency radio systems with electromagnetic interference (EMI). EMI can be very critical when switching power radios utilize backup receivers, which are used as aircraft backup systems or airport last-resort systems. The switching power electronics process produces interfering electromagnetic energy to create problems with onboard aircraft radios or instrument landing system (ILS) avionics services. Analyses demonstrate significant threats and risks resulting from interferences between radio and power electronics in airborne systems. Results demonstrate the impact of interferences on intermediate-frequency processing, namely, for very high frequency (VHF) radios. The paper also describes the methodology of testing radio immunity against both weak and strong signals in accordance with recent aviation standards and guidance for military radio communication systems in the VHF band.

Justification of the methodological bases for the management of the radio resource of special purpose radio communication systems under conditions of prior uncertainty

The problem of substantiation of methodological bases of radio resource management of military radio communication systems in the conditions of a priori uncertainty is solved in the work. The object of research is the military radio communication system. One of the most problematic places in the management of military radio resources is the inability to carry out a hierarchical management of the parameters and modes of operation of both individual radios and the military radio system as a whole. This reduces the efficiency of the system itself and the efficiency of its application. The scientific problem is solved by substantiating the methodological principles of radio resource management of military radio communication systems in conditions of a priori uncertainty. During the research, the authors used the main provisions of the theory of queuing, the theory of automation, the theory of complex technical systems, as well as general scientific methods of cognition, namely analysis and synthesis. The novelty is that in the course of work: – the purpose of functioning of an operative management subsystem of a radio resource of military radio communication systems is formulated; – indicators and criteria of functioning efficiency of military radio communication systems are determined; – decomposition of the solution of this problem into problems depending on the signal and noise situation is carried out. An approach based on the hierarchical decomposition of the functional structure of networks, the behavior of which is described by stochastic differential (or difference) equations of the high dimension state, into a number of interconnected but simpler functional structures is used for the functional description of military radio communication systems. It will allow to make a decomposition of the state of the military radio system and increase the efficiency of decision-making on adjusting the modes of operation and parameters of the military radio system in real time. The research results should be used at the stage of operational management of parameters and modes of these systems operation.

Development of a method of adaptive control of military radio network parameters

A method of adaptive control of military radio network parameters has been developed. This method allows predicting suppressed frequencies by electronic warfare devices, determining the topology of the military radio network. Also, this method allows determining rational routes of information transmission and operating mode of radio communications. Forecasting of the electronic environment is characterized by recirculation of input data for one count, resampling on a logarithmic time scale, finding a forecast for the maximum value of entropy and resampling the forecast on the exponential time scale. The developed method allows choosing a rational network topology. The choice of topology of the military radio communication system is based on the method of ant multi-colony system. The main idea of the new option of ant colony optimization is that instead of one colony of the traditional ant algorithm several colonies are used that work together in a common search space. However, this procedure additionally takes into account the type of a priori uncertainty and the evaporation coefficient of the pheromone level. The proposed method allows choosing a rational route for information transmission. The proposed procedure is based on an improved DSR algorithm. This method uses several operating modes of radio communications, namely the technology of multi-antenna systems with noise-like signals, with pseudo-random adjustment of the operating frequency and with orthogonal frequency multiplexing. The developed method provides a gain of 10‒16 % compared to conventional management approaches

Эффективность применения помехоустойчивого кодирования в системах передачи цифровой информации с широкополосными сигналами.

The method of transmitting information using broadband signals is recognized as an effective way to combat various types of organized intentional and unintentional interference. Among them, methods for transmitting digital information with frequency-hopping spread spectrum (FHSS) have found wide application. Due to its frequency and energy efficiency, the transmission method with frequency hopping is widely used in information transmission systems for various purposes, including military radio communication systems (RCS), where high interference immunity is required. Both when transmitting digital information under the conditions of the destructive effect of electronic suppression means, and without this effect, the received data sequence contains errors. To detect and correct them, noise-correcting coding is effective. The article considers the case when at the input of the receiver, in addition to its own noise, there is also a deliberate concentrated partial-band noise jamming, occupied by the RCS. An analysis is made of the noise immunity of a RCS with a frequency hopping and DBPSK with the combined use of error-correcting coding and time-frequency diversity of the code symbol. The application in the analyzed RCS of the algorithm of incoherent reception of diversity signals with weight processing and subsequent decoding is considered. It’s shown that the noise immunity of the RCS under the considered conditions turns out to be significantly higher than the RCS, in which the frequency diversity of the code symbol and the noise-immune coding are not used.