통합 군 통신 시스템에서 상호운용으로 인한 간섭 영향 분석

Hybrid spread-spectrum (HSS) systems have recently received considerable interest in commercial, Smart Grid, and military communication systems because they accommodate high data rates with high link integrity, even in the presence of significant multipath effects and interfering signals. A highly useful form of this modulation scheme is the specific code-related combination of standard direct-sequence spread spectrum (DSSS) with fast frequency-hopping (FFH) spread spectrum, denoted hybrid DS/FFH, wherein multiple frequency hops occur within a single data-bit time. In this paper we perform a simulation-based study of the DS/FFH performance as compared to the existing standard DSSS and FHSS wireless networks. The performance metrics are biterror probability and multiple-access capability. The parameter space of DS/FFH, including the DS spreading rate, frequency hopping rate, carrier frequencies, and numbers of users, is explored to show its performance under frequency-selective Rayleigh fading environments and multiuser interference. Direct digital synthesizers to achieve fast hopping speeds are also considered in our study.

Preface. 1 Spread spectrum signals and systems. 1.1 Basic definition. 1.2 Historical sketch. 2 Classical reception problems and signal design. 2.1 Gaussian channel, general reception problem and optimal decision rules. 2.2 Binary data transmission (deterministic signals). 2.3 M-ary data transmission: deterministic signals. 2.4 Complex envelope of a bandpass signal. 2.5 M-ary data transmission: noncoherent signals. 2.6 Trade-off between orthogonal-coding gain and bandwidth. 2.7 Examples of orthogonal signal sets. 2.8 Signal parameter estimation. 2.9 Amplitude estimation. 2.10 Phase estimation. 2.11 Autocorrelation function and matched filter response. 2.12 Estimation of the bandpass signal time delay. 2.13 Estimation of carrier frequency. 2.14 Simultaneous estimation of time delay and frequency. 2.15 Signal resolution. 2.16 Summary. Problems. 3 Merits of spread spectrum. 3.1 Jamming immunity. 3.2 Low probability of detection. 3.3 Signal structure secrecy. 3.4 Electromagnetic compatibility. 3.5 Propagation effects in wireless systems. 3.6 Diversity. 3.7 Multipath diversity and RAKE receiver. Problems. 4 Multiuser environment: code division multiple access. 4.1 Multiuser systems and the multiple access problem. 4.2 Frequency division multiple access. 4.3 Time division multiple access. 4.4 Synchronous code division multiple access. 4.5 Asynchronous CDMA. 4.6 Asynchronous CDMA in the cellular networks. Problems. 5 Discrete spread spectrum signals. 5.1 Spread spectrum modulation. 5.2 General model and categorization of discrete signals. 5.3 Correlation functions of APSK signals. 5.4 Calculating correlation functions of code sequences. 5.5 Correlation functions of FSK signals. 5.6 Processing gain of discrete signals. Problems. 6 Spread spectrum signals for time measurement, synchronization and time-resolution. 6.1 Demands on ACF: revisited. 6.2 Signals with continuous frequency modulation. 6.3 Criterion of good aperiodic ACF of APSK signals. 6.4 Optimization of aperiodic PSK signals. 6.5 Perfect periodic ACF: minimax binary sequences. 6.6 Initial knowledge on finite fields and linear sequences. 6.7 Periodic ACF of m-sequences. 6.8 More about finite fields. 6.9 Legendre sequences. 6.10 Binary codes with good aperiodic ACF: revisited. 6.11 Sequences with perfect periodic ACF. 6.12 Suppression of sidelobes along the delay axis. 6.13 FSK signals with optimal aperiodic ACF. Problems. 7 Spread spectrum signature ensembles for CDMA applications. 7.1 Data transmission via spread spectrum. 7.2 Designing signature ensembles for synchronous DS CDMA. 7.3 Approaches to designing signature ensembles for asynchronous DS CDMA. 7.4 Time-offset signatures for asynchronous CDMA. 7.5 Examples of minimax signature ensembles. Problems. 8 DS spread spectrum signal acquisition and tracking. 8.1 Acquisition and tracking procedures. 8.2 Serial search. 8.3 Acquisition acceleration techniques. 8.4 Code tracking. Problems. 9 Channel coding in spread spectrum systems. 9.1 Preliminary notes and terminology. 9.2 Error-detecting block codes. 9.3 Convolutional codes. 9.4 Turbo codes. 9.5 Channel interleaving. Problems. 10 Some advancements in spread spectrum systems development. 10.1 Multiuser reception and suppressing MAI. 10.2 Multicarrier modulation and OFDM. 10.3 Transmit diversity and space-time coding in CDMA systems. Problems. 11 Examples of operational wireless spread spectrum systems. 11.1 Preliminary remarks. 11.2 Global positioning system. 11.3 Air interfaces cdmaOne (IS-95) and cdma2000. 11.4 Air interface UMTS. References. Index.

The subject of research in this article is the process of building a mobile communication system that operates under electronic countermeasures. The aim is to develop recommendations for building a wireless mobile communication system that operates effectively in a complex interfering electromagnetic environment. The strategy for building a mobile wireless communication system is based on the use of a grouping of low-altitude UAVs with ultra-wideband signal technology circulating in control and communication channels, with the integration of artificial intelligence elements into its structure. The objective of this study is to ensure the stable and secure operation of a wireless mobile communication system despite electronic countermeasures. The methods of analytical, temporal positional pulse coding, and fuzzy logical inference were used to make decisions on the transfer of service in the network. The following results were obtained. A strategy for building a wireless mobile communication system despite electronic countermeasures has been developed. It is shown that in order to obtain high noise immunity of control and communication channels and to protect information from interception, wireless ultra-wideband communication technology should be used. This will provide large volumes and speeds of information transmission. A technical solution for the design of an ultra-wideband transceiver antenna system is proposed. Moreover, it is recommended to use the results of data processing in a fuzzy decision-making system for the transfer of service between mobile network nodes in conditions of interference. Conclusions. The scientific novelty of the obtained results is as follows. The use of ultra-wideband channels makes it possible to increase the number of control and communication channels in a wireless mobile system almost unlimitedly. The preliminary distribution of orthogonal codes between the channels realizes the process of control and communication without the interception of information and mutual interference. The use of the time-position-pulse coding method prevents the occurrence of intercharacter distortions of the encoding ultrashort pulses. This also reduces the level of distortion of information signals caused by multipath propagation, which guarantees the security of information in the system. The use of a fuzzy decision-making system for the transfer of services between mobile network nodes allows dynamically changing the network topology in real time and maintaining high quality of service under electronic countermeasures.

The article deals with the issues of interference and intelligence protection of radio communication means of the mobile component of the tactical command and control link in the conditions of active use of electronic warfare. The problems arising from the use of standard radio communication means that do not provide a sufficient level of protection against intentional interference and interception of signals by the enemy are analysed. The necessity of developing a scientific and methodological apparatus for adapting the radio networks of the National Guard of Ukraine to the conditions of active interference is substantiated. An analysis of modern radio communication equipment used in the military, including portable radios, satellite communication systems, tactical Wi-Fi solutions and software-based radio networks, is carried out. It is determined that the existing communication systems do not provide effective counteraction to enemy radio jammers, especially in direct contact. A new method of spatial interference rejection based on the optimal location and direction of antenna systems of ground-based transmitters and receivers of UHF/VHF and Wi-Fi radio signals is proposed. The proposed method takes into account the tactical situation, the territorial location of radio network nodes and allows to increase the interference immunity of radio channels by changing the characteristics of antenna systems. A mathematical model of interaction between the elements of the radio communication system and active radio masking means is substantiated, which allows determining the optimal parameters of antenna systems and radiation power. The threshold values of the suppression coefficient are determined, at which the required quality of signal reception is guaranteed under the conditions of targeted concentrated interference. The concept of a stable radio communication zone is expanded, in particular, the dependence of its area on the shape of the radiation pattern and the distance between the elements of the communication system is substantiated. For the first time, a comprehensive analysis of the combined effect of intentional interference and active radio jamming on the stability of radio channels is carried out, which allows a reasonable approach to planning radio communications in the conditions of electronic warfare. An algorithm for determining the area of stable exchange for the points of the operational map of combat operations is proposed, which allows to effectively plan the location of communication means and active radio masking means. The practical significance of the obtained results lies in the possibility of applying the developed method in the creation of adaptive radio communication systems that take into account the real tactical situation, which can significantly increase the efficiency of troop management in the conditions of information influence of the enemy.

Detection devices are becoming more wideband, faster scanning and their signal processing capabilities are increasing. In addition, sophisticated jamming devices have become rather powerful. As a consequence, threats to military radio communications have increased such that it is about time to discuss what features future military radio systems should have in order to battle against these increased menaces. This paper fills this gap by considering this problem from the point of view of electronic warfare physics. The result is a set of features that would help in the engagement. Furthermore, it discusses what effects these features have for radio system design. The proposed features add new properties, compared with legacy radios, that require new control functionalities that have to cooperate with old ones as well as together and also add radio hardware. Therefore, corresponding research problems will not be easily solved.

Physical layer security (PLS) in wireless communication systems has attracted extensive research attentions in recent years. Unlike cryptography-based methods applied in upper-layer in network, PLS methods are applied in physical layers and can provide information-theoretic security by utilizing the randomness of signals and wireless channels. In this survey, we provide a comprehensive review in the domain of physical layer authentication (PLA) in wireless communication systems, including the concepts, several key techniques of typical PLA architectures as well as future challenges and research trends in more sophisticated communication systems. The survey begins with an overview of the background and basic concepts of PLA, such as the general model of wireless security communication system, typical frameworks of key-based/less PLA systems, and the common attack models. We then discuss the major concerns and key techniques that are applied in PLA systems, where three types of authentication schemes are considered, i.e., the authentication based on channel information, radio-frequency and identity watermarks. Basic models and representative research results about key approaches and techniques applied to the authentication systems above are subsequently covered. Finally, the associated challenges and potential research trends of PLA in future communication systems are presented at the end of the survey paper.

Vehicle-to-vehicle and vehicle-to-infrastructure wireless communications are currently under development to improve traffic efficiency and safety. The time-critical nature of road safety applications imposes the need to accurately dimension the operation and performance of wireless vehicular communication systems. Given that radio propagation modeling has been shown to importantly affect the performance of traditional mobile and wireless communication systems, this work investigates its impact on the dimensioning of traffic safety wireless vehicular communications by separately analyzing the contributions of pathloss, shadowing and fast fading.

The engineer designing a new communications system often has available a choice between several different types of RF modulation. The four main methods considered here are standard amplitude (AM), double-sideband suppressedcarrier (DSBSC), single-sideband (SSB), and frequency (FM) modulations. Some of their basic system performance characteristics are evaluated on a comparative basis for the transmission of voice and pulsed data. Factors considered include: compatibility, effective range, bandwidth, signal-to-noise performance, interference rejection capabilities, distortion characteristics, required stability, required transmitter power, and resulting circuit complexity. The choice of the best type of modulation for a particular communications system requires the simultaneous consideration of many such factors evaluated for the basic requirements of that system. Because these factors vary with system parameters and because they may be of differing relative importance, it is not possible to say that any one type of modulation is best for all uses. The practical manner in which the choice may be made is illustrated by examples drawn from several types of communication systems.

In the rapidly growing domain of wireless communication, data security has emerged as a critical requirement, especially in resource-constrained embedded systems. This paper proposes a secure wireless communication system based on ZigBee technology and Advanced Encryption Standard (AES), implemented using Arduino microcontrollers. The system comprises a transmitter that accepts data via a keyboard, encrypts it using AES-128, and transmits it wirelessly via ZigBee. The receiver decrypts the data and displays it on an LCD. Leveraging ZigBee’s low-power and low-data-rate characteristics, the design ensures secure, efficient, and scalable communication suitable for applications such as home automation, military systems, and industrial control. The integration of AES encryption ensures end-to-end data confidentiality without significantly impacting transmission speed or energy consumption. Performance evaluation confirms the system’s viability for Internet of Things (IoT) applications demanding both security and efficiency. Keywords: Wireless Communication, ZigBee Protocol, AES-128 Encryption, Arduino Microcontroller, Secure Data Transmission, End-to-End Encryption.

The article presents the general provisions and essence of the approach to building a mathematical model of the functioning of an automated military radio communication system in the process of its protection against radio reconnaissance by radio exchange along rational routes. The main components of the mathematical model of the functioning of an automated military radio communication system in the process of its protection against radio reconnaissance by radio exchange along rational routes with low intelligence availability are considered. The general structure of a mathematical model of the functioning of an automated military radio communication system in the process of its protection against radio reconnaissance by radio exchange along rational routes is proposed. It is shown that in the basic modeling unit of the subprocess of determining the rational routes of radio exchange among the set of possible ones, an optimization problem is solved. The result of solving this optimization problem is presented in tabular form for convenience. The analytical expressions for the third-rank tensor of the intelligence accessibility of individual branches of the radio communication system structure are obtained.

A novel spread spectrum (SS) system based on the unconventional self encoding principle has been proposed for highly secured data transmissions. This system inherits the antijamming (AJ) and low probability of interception (LPI) characteristics like any other SS system with the aid of truly random spreading codes, which are generated from the source stream itself. Therefore, the proposed system is unique in that the traditional transmit and receive PN code generators are not needed. In fact, the enhanced transmission security arises not only due to the SS nature of the signal, but also from the true randomness of the unique spreading processes. This paper describes the proposed system and presents the simulation results of the system performance under various kinds of jamming conditions, which is not been so far dealt. The obtained performance curves are compared with existing SS systems like direct sequence and frequency hopped SS.

The rapid development of sophisticated military command and control systems causes the dynamic demand for broadband services including the transmission of video in real time by using telecommunications links. One way to resolve the problem of limited bandwidth in used military wireless systems is to use modern broadband radio stations. Broadband radio stations in addition to undoubted advantages such as increased system bandwidth, have also some limitations – in comparison to narrowband radios, broadband radios offer a smaller range and work in a wide band and high transmitter activity associated with the generation of maintenance traffic, which makes it easier to detect radio emission by the opponent. Modern electronic warfare systems can track down such systems and overpower them. That is why one of the main tasks, which currently are facing designers of advanced broadband radio communication systems, is to develop mechanisms to immunize broadband radio stations on the targeted interference. In this article the method of implementation of the national waveform allowing for securing the transmission in broadband radio stations will be presented. Transmission modes of the radio station (TDMA, CSMA/SC, CSMA/MC) will be discussed considering advantages and disadvantages of each of the above-mentioned modes of operation. In the next chapter selected results of experimental studies of broadband radio station R-450C with the above-mentioned implemented operating modes and universal defeat device for generation of diverse broadband interference will be presented. The obtained results will allow to assess the implemented modes of radio stations for resistances of broadband radio communication system on selected targeted interference. The developed analysis and obtained measurement results may be helpful both for people organizing radio communication using broadband radios as well as for those responsible for the proper operation of electronic warfare systems.

SummaryThis paper introduces the concept of spatial and media‐based modulated (SMBM) orthogonal frequency division multiplexing (OFDM) as a potential candidate for highly mobile next generation beyond 5G (B5G) wireless communications. The proposed SMBM‐OFDM technique utilizes not only the transmit antenna and channel state indices but also OFDM subcarriers to improve the system performance under high mobility. In addition, this study sheds light on challenging fast time‐varying channel estimation problem of MBM‐based systems by using the linear minimum mean square error (LMMSE) approach due to its optimality to investigate the achievable system performance with the aid of basis expansion modeling. The minimum lower bound on the channel estimation error (Bayesian Cramer–Rao bound) is derived theoretically and shown to be attainable by the considered LMMSE estimator. Moreover, symbol detection performance is provided for different modulation types and higher mobile velocities. Simulation results demonstrate that SMBM‐OFDM system under high mobility is able to provide around 12‐dB performance gains in terms of both channel estimation and symbol detection error compared to conventional spatial modulation (SM)‐OFDM systems without MBM. The presented framework is important due to addressing the high mobility support of SMBM‐OFDM systems for B5G wireless communications in terms of achievable channel estimation and data detection performance.

We designed and implemented a deep learning based RF signal classifier on the Field Programmable Gate Array (FPGA) of an embedded software-defined radio platform, DeepRadio™, that classifies the signals received through the RF front end to different modulation types in real time and with low power. This classifier implementation successfully captures complex characteristics of wireless signals to serve critical applications in wireless security and communications systems such as identifying spoofing signals in signal authentication systems, detecting target emitters and jammers in electronic warfare (EW) applications, discriminating primary and secondary users in cognitive radio networks, interference hunting, and adaptive modulation. Empowered by low-power and low-latency embedded computing, the deep neural network runs directly on the FPGA fabric of DeepRadio™, while maintaining classifier accuracy close to the software performance. We evaluated the performance when another SDR (USRP) transmits signals with different modulation types at different power levels and DeepRadio™receives the signals and classifies them in real time on its FPGA. A smartphone with a mobile app is connected to DeepRadio™to initiate the experiment and visualize the classification results. With real radio transmissions over the air, we show that the classifier implemented on DeepRadio™achieves high accuracy with low latency (microsecond per sample) and low energy consumption (microJoule per sample), and this performance is not matched by other embedded platforms such as embedded graphics processing unit (GPU).

In order to solve the problems of low-risk assessment accuracy and long time-consuming assessment of current wireless mobile communication systems, a wireless mobile communication system based on artificial intelligence algorithms is proposed. First, the research status of risk assessment of wireless mobile communication system at home and abroad is analyzed, and the risk assessment index system of wireless mobile communication system is established; then, the learning samples are collected according to the risk assessment index system of wireless mobile communication system, and artificial intelligence algorithm is used to optimize the neural network. Build the wireless mobile communication system risk assessment model; finally, carry out the wireless mobile communication system risk assessment simulation comparison test. The experimental results show that the accuracy rate of the risk assessment of the wireless mobile communication system by the artificial intelligence algorithm is over 95%, and the assessment error is smaller than in other models. The risk assessment time of the wireless mobile communication system is significantly reduced, the real-time performance is better, and it has a higher practical application value.