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В статье рассматриваются предложения по построению аналоговой части SDR радиоприёмных устройств декаметрового диапазона, обеспечивающих требования стандарта, предъявляемых к радиоприёмным средствам декаметрового диапазона в части динамического диапазона входного сигнала и уровня восприимчивости по блокированию, а также устраняющие искажения, вносимые автоматической регулировкой усиления при приёме сигналов системы радиосвязи с использованием режима изменения рабочей частоты по псевдослучайному закону. Целью работы является анализ структуры аналоговой части SDR радиоприёмных устройств декаметрового диапазона и требований, предъявляемых к её отдельным составляющим. Используемые методы: теоретический и практический заделы в области цифровой обработки сигналов декаметрового канала связи. Новизна: состоит в том, что предлагаются структура аналоговой части SDR радиоприёмных устройств декаметрового диапазона. Результат: заключается в том, что предлагаемая структура аналоговой части SDR радиоприёмных устройств обеспечивает как предъявляемые требования стандарта и позволяет обеспечить работу систем связи с изменением рабочей частоты по псевдослучайному закону во всём декаметровом диапазоне. Практическая значимость: заключается в том, что предлагаемая структура аналоговой части SDR радиоприёмных устройств декаметрового диапазона позволит обеспечить построение систем декаметровой связи, обеспечивающих заданные вероятностно-временные характеристики в условиях радиоэлектронного противоборства и решающие проблему электромагнитной совместимости., The article includes proposals for the construction of the industrial part of SDR decameter radio receivers, recommended standard requirements for HF radio in terms of the dynamic range of the input signal and the level of blocking susceptibility, as well as damaging distortions introduced by AGC when receiving signals from a radio communication system with FHSS. The purpose of this work is to analyze the structural part of the SDR radio receivers of decameter and safe components suitable for its use. Methods used: theoretical and practical groundwork in the field of digital signal processing of a decameter communication channel. Novelty: consists in the fact that the structure of the analog part of the SDR radio receivers of the decameter range is proposed. Result: is that the proposed structure of the analog part of the SDR radio receivers provides both the requirements of the standard and allows you to ensure the operation of communication systems with FHSS in the entire decameter range. Practical significance: lies in the fact that the proposed structure of the analog part of the SDR HF radio receivers will ensure the construction of decameter communication systems that provide the specified probabilistic-temporal characteristics in the conditions of Electronic countermeasures and solve Electromagnetic compatibility problems.

Последовательное расширение спектра сигналов давно зарекомендовало себя как надежный способ борьбы с «плохим» распространением сигнала на одной несущей частоте. Используя несколько несущих частот, можно эффективно бороться со многими мешающими факторами искусственного и естественного происхождения. В статье ставится задача оценки эффективности применения последовательного расширения спектра сигнала в модеме при использовании радиосредств с различным временем переключения несущей частоты. Целью работы является создание модели передающей и приёмной части радиомодема с последовательным расширением спектра сигнала, которая учитывает длительность перехода с одной рабочей частоты на другую. При моделировании использовались методы цифровой обработки сигналов и теории связи. Новизна решения состоит в сопоставлении двух способов модуляции и оценки помехоустойчивости работы радиомодема. К результатам работы следует отнести программную реализацию радиомодема в виде объектно-ориентированного кода для вычислительной среды технических расчетов MATLAB. Практическая значимость работы заключается в том, что определен характер изменения помехоустойчивости при различном времени переключения несущей частоты. Результаты работы могут использоваться при разработке аппаратуры передачи данных для радиосвязи., The frequency-hopping spread spectrum is a reliable way to work in non-stationary communication channels. By using multiple carrier frequencies, it is possible to work in a poor communication channel with natural and man-made noise. The article aims to consider the boundaries of frequency-hopping spread spectrum usage in radio modem when using radio transceivers with different carrier frequency switching times. The main goal of this work is to create a model of the transmitting and receiving part of the radio modem with frequency-hopping spread spectrum that takes into account the time of the carrier frequency changing. In modeling, methods of communication theory and digital signal processing are used. The novelty of the solution is to compare two types of modulation and calculation of bit error rate in different situation. The result of the work is a software solution of a part of the radio modem, which runs in MATLAB. The practical significance of the work is to define the bit error rate it depends on time of changing of carrier frequency. The results of the work are possible to use in the development of data transmission equipment for radio communications.

U ovome radu opisani su dronovi kroz povijest, dana je njihova podjela te moguća primjena raznim područjima i opisane su njihove značajke. Također opisan je bežični prijenos informacija te njegovi dijelovi. Zatim su opisane smetnje odnosno interferencije koje utječu na kvalitetu signala, a samim time i domet bespilotne letjelice. Shodno tome opisane su metode koje se koriste kako bi se otklonile ili smanjile smetnje, kao modulacije multipleksiranje i prošireni spektar. Nadalje, navedene su značajke FHSS i DSS, odnosno metode koje služe za proširivanje spektra. Opisan je i WLAN i Bluetooth, tehnologije koje se koriste na frekvenciji od 2,4 GHz. U praktičnom dijelu rada ispitano je ponašanje drona DJI Mavic Mini drona u raznim uvjetima i ispitani su komunikacijski parametri u pojasu 2,4 GHz te je napravljen proračun veze na toj frekvenciji. A proračun je provjeren mjerenjima u stvarnim uvjetima. Zaključak je da Wireless signali i prepreke imaju velik utjecaj na kvalitetu veze za razliku od Bluetooth signala čiji je utjecaj gotov zanemariv u odnosu na WLAN signale. This esay describes drones trough the history, their types, possible usage in different areas and also describers their preferences. It also describes wireless dana transfer and its parts. Further it desribes interferences which have impact on signal quality and range of dron by itself. After that it describes methods which are used to remove interfereneces or make them lower, those methods are modulation, multiplexing and te use of the extended spectrum. It also describes preferences or methods for spread spectrum like FHSS and DSSS. WLAN and Bluetooth technologies that are used on 2,4 Ghz frequency are described too. In practical part of esay DJI Mavic Mini drone behavior is tested in different conditions and communication parametars are mesured in 2,4 GHz range , also link budget on that frequency was resolved and checked in real conditions. Where conclusion was that wireless signals and also obstacales have big impact on quality of the connection, different from Bluetooth signals which don't interfere with quality of the signal almost at all in comparasion with wifi signals.

This paper presents performance evaluation and comparison analysis of Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS) systems. The evaluation and analysis are done based on the systems performance against wideband interferences. The interferences are signals with similar spectrum characteristic to the transmitted signals of DSSS and FHSS systems. Bit Error Ratio (BER) is used as evaluation parameter to assess the performance of both systems. Simulation and mathematical analysis are performed to test and verify the performance of both systems. Mathematical analysis also verifies that increasing Spreading Frequency on certain conditions will reduce the BER. This research also points out that FHSS system has a better performance compared to DSSS system indicated by smaller BER.

Given the inherent need to have technological tools to reduce the number of incidents caused by the operation of heavy machinery, this document briefly describes the design of a prototype Accident Prevention System for industrial vehicles using Radio Frequency Identification Technology (RFID). ) that warns about the proximity of people to the area of operation of industrial equipment, the deployment of Open Source technology provides the necessary resources for a Raspberry Pi 3 B + control device to execute information processing through a control interface that will activate an alarm and through a management module the RFID components (TAGS and Readers) will be managed and the reports of the readings will be obtained. Finally, considering factors such as frequency, the operating environment, the type of modulation, the antenna height, the radiation pattern of the antenna, the antenna gain and the receiver gain influence the propagation of the waves radio will perform a predictive investigation in different scenarios by means of an estimation of the coverage based on the model of propagation of loss in free space to verify the reliability of the prototype that operates with Ultra Narrow Band technology and employs techniques of Spread Spectrum by Jump Frequency.

Frequency Hopping Spread Spectrum (FHSS) signaling is used across many devices operating in both regulated and unregulated bands. In either situation, if there is a malicious device operating within these bands, or more simply a user operating out of the required specifications, the identification this user important to insure communication link integrity and interference mitigation. The identification of a user involves the grouping of that users signal transmissions, and the separation of those transmission from transmissions of other users in a shared frequency band. Traditional signal separation methods often require difficult to obtain hardware fingerprinting characteristics or approximate geo-location estimates. This work will consider the characteristics of FHSS signals that can be extracted directly from signal detection. From estimates of these hopping characteristics, novel source separation with classic clustering algorithms can be performed. Background knowledge derived from the time domain representation of received waveforms can improve these clustering methods with the novel application of cannot-link pairwise constraints to signal separation. For equivalent clustering accuracy, constraint-based clustering tolerates higher parameter estimation error, caused by diminishing received signal-to-noise ratio (SNR), for example. Additionally, prior work does not fully cover the implications of detecting and estimating FHSS signals using image segmentation on a Time-Frequency (TF) waterfall. This work will compare several methods of FHSS signal detection, and discuss how each method may effect estimation accuracy and signal separation quality. The use of constraint-based clustering is shown to provide higher clustering accuracy, resulting in more reliable separation and identification of active users in comparison to traditional clustering methods. Master of Science The expansion of technology in areas such as smart homes and appliances, personal devices, smart vehicles, and many others, leads to more and more devices using common wireless communication techniques such as WiFi and Bluetooth. While the number of wirelessly connected users expands, the range of frequencies that support wireless communications does not. It is therefore essential that each of these devices unselfishly share the available wireless resources. If a device is using more resources than the required limits, or causing interference with other’s communications, this device will impact many others negatively and therefore preventative action must be taken to prevent further disruption in the wireless environment. Before action can be taken however, the device must first be identified in a mixture of other wireless activity. To identify a specific device, first, a wireless receiver must be in close enough proximity to detect the power that the malicious device is emitting through its wireless communication. This thesis provides a method that can be used to identify a problem user based only off of its wireless transmission behavior. The performance of this identification is shown with respect to the received signal power which represents the necessary range that a listening device must be to identify and separate a problem user from other cooperative users that are communicating wirelessly.

Introduction. In the process of warfare the system and radio communications are used in a complex electronic environment. The former is created by the great amount of natural and man-made obsticles . Recently means of radio communication with a FHSS have become more widespread as they provide more reliable connection and protect the signal from obstacles . The effectiveness of hindrance influence on the radio communication system (RCS) with FHSS is achieved by intercepting the signal and determining its parameters. A malefactor obtains these parameters via electronic intelligence station (EIS). The aim of the article is to assess the probability of interception single signal transmitter hops from FHSS using searcher receiver. The subject of the study is a searcher, the product of Rohde & Schwarz (R&S) company, and a spectrum analyzer RTSA, which search for signals from a transmitter with hopping mode. The probability of intercept for a single signal in a single trial. We consider the probability of intercepting signals of single- and multi-channel transmitter for single frequency hopping in different types of overlapping frequency ranges. For these cases the analytical expressions are presented. The probability of intercept for a single signal in multiple testing. According to the presented analytical expressions, calculation of the probability of interception of single signal hop when scanning receiver for implementing a hop of more than one dimension is carried out. Calculating the probability of intercepting a single signal during a few tests. We calculated the probability of signal interception from the station "Aqueduct" with the help of the spectrum analyzer RSA6114A during the test series. Conclusions. As a result of research we analyzes the limits and expanded use of methods of detection signals FHSS mode for cases where the frequency band of the transmitter and the receiver position is not the same., В процессе ведения боевых действий системы и средства военной радиосвязи сталкиваются с рядом проблем по обеспечению надежного функционирования систем связи. Это связано со сложной радиоэлектронной обстановкой, что обусловлено природными и преднамеренными помехами. Одним из эффективных методов повышения помехозащищенности радиолиний при воздействии преднамеренных помех является применение псевдослучайной перенастройки рабочей частоты (ППРЧ). В статье проводится анализ известной методики обнаружения сигналов передатчика с ППРЧ и расширение границ использования данной методики в случае, когда полосы частот передатчика подавляемой СРС и сканирующего приемника станции РТР не совпадают., У процесі ведення бойових дій системи та засоби військового радіозв’язку стикаються з низкою проблем по забезпеченню надійного функціонування систем зв’язку. Це пов’язано з складною радіоелектронною обстановкою, що зумовлюється природними і навмисними завадами. Одним з ефективних методів підвищення завадозахищеності радіоліній при впливі навмисних завад є застосування псевдовипадкового переналаштування робочої частоти (ППРЧ). У статті проводиться аналіз відомої методики виявлення сигналів передавача з ППРЧ та розширення меж використання даної методики у випадку, коли смуги частот передавача придушуваної СРЗ та скануючого приймача станції РТР не співпадають.

U ovom radu je opisan bežični prijenos informacija i dijelovi od kojih se prijenosni sustav sastoji. Opisane su interferencije koje ometaju komunikaciju i metode pomoću kojih sustav postaje otporniji na te smetnje, kao što su : multipleksiranje, modulacije i korištenje proširenog spektra. Zatim glavne metode proširivanja spektra: DSSS i FHSS. Opisane su i tehnologije koje rade na frekvenciji od 2, 4 GHz: Wlan i Bluetooth, koje su ujedno i glavni izvor interferencija u praktičnom dijelu rada. U praktičnom dijelu rada su opisan parametri bespilotne letjelice. U laboratoriju su izmjereni frekvencijsko područje i snaga upravljača. Domet i utjecaj interferencije su mjereni u slabije naseljenom području, gdje se došlo do zaključka da prepreke kao što su zidovi i Wlan signali značajno utječu na prijenosni sustav, dok Bluetooth signali imaju zanemariv utjecaj.

International audience; In order to detect and locate a receiver relative to a grid of transmitters in an underwater environment, it is necessary to detect each signal emitted by each transmitter and estimate its Time Of Arrival (TOA) and estimate the position through triangulation. The choice of the signals and their modulation is then crutial to have a good estimation of the TOA and reduce false alarms. This paper focuses on FHSS (Frequency Hopped Spread Spectrum) modulations and compares the performances of several codes, by using a criterion proposed in this paper. It proposes finally to adapt the best FHSS signal in a multi-users context.

Frekvencijski pojasevi koji su ostavljeni za industrijske, medicinske i znanstvene svrhe nazivaju se ISM pojasevi. Oni su slobodni za korištenje, i najpoznatiji od njih je 2,4 GHz frekvencijski pojas. Mikrovalna pećnica, WLAN, Bluetooth samo su neki od uređaja koji rade na području frekvencija 2,4 GHz pojasa. Bluetooth tehnologija je kratkodometna bežična radijska komunikacija za razmjenu podataka, koja radi na rasponu frekvencija od 2,4 GHz - 2,4835 GHz. Prva verzija Bluetooth tehnologije bila je v1.0, a danas posljednja je v4.2. Domet Bluetooth-a danas doseže otprilike 100 metara. Bluetooth uređaji kada žele komunicirati, uspostavljaju mrežu zvanu piconet , gdje jedan uređaj upravlja komunikacijom, te on postaje nadređenim, dok ostali se zovu podređeni. Više piconet mreža tvori scattenret mrežu. Prilikom uspostavljanja mreže, Bluetooth uređaji prolaze kroz određeni broj stanja, pri čemu tijekom komunikacije moraju biti sinkronizirani. Primjena je Bluetootha raznolika, koristi se u većini elektroničkih uređaja koji koriste baterije kao napajanje. Neki od uređaja koji koriste Bluetooth su mobilni telefoni, računala, laptopi, tableti, tipkovnice, miševi, slušalice, u automobilima i još mnoštvo drugih uređaja. Kako je 2,4 GHz slobodan za korištenje, često je napučen korisnica čime dolazi do smetnji između uređaja. Kako bi se smetnje izbjegle, Bluetooth koristi modulacijsku tehniku frekvencijskog skakanja s raspršenim spektrom (FHSS). Raspoloživi raspon od 83,5 MHz se podijeli u 79 kanala, širine 1 MHz. Podatak se u pojedinom kanalu zadrži 625 us, nakon čega skače na drugu frekvenciju. Frekvencije se mijenjaju do 1600 puta u sekundi, čime su male šanse da će doći do smetnje i gubitka podataka. Postupak frekvencijskog skakanja se može simlurati i ispitati programskim alatom MATLAB, gdje je moguće vidjeti utjecaje modulacije i kodiranja podataka, koji prolaze kroz kanal sa šumovima. Simulacijom se uvidjelo da najveći utjecaj na pogreške upravo imaju šumovi. Frequency bands that are left for industrial, medical and scientific purposes are called ISM bands. They are free ti use, and the most famous of them is 2,4 GHz frequency band. The microwave oven, WLAN, Bluetooth are only some of devices that are operating in the frequency range of the 2,4 GHz band. Bluetooth technology is a short-range wireless radio communication for data exchange, which works on the frequency range of 2,4 GHz - 2,4835 GHz. The first version of Bluetooth technology was v1.0, and today the latest is v4.2. The range of bluetooth today reaches about 100 meters. When Bluetooth devices want to communicate, they establish a network called piconet, where one device handles the communication, and it becomes the master, while the others are called slaves. More piconet networks form scatternet network. While establishing networks, Bluetooth devices go through a number of states, whereby, during the communication they must be synchronized. The use of Bluetooth is diverse, it is mostly used in electronic devices that use batteries as their power supply. Some of the devices that use Bluetooth are mobile phones, computers, laptops, tablets, keyboards, mice, headsets, in the cat and many other devices. As the 2,4 GHz is free to use, it is often crowded by users which is causing interference between devices, To avoid interference, Bluetooth uses the frequency hopping spread spectrum modulation technique. The range of 83,5 MHz is divided into 79 channels, with width of 1 MHz. The data in each channel is 625 us kept, afther that it jumps to an another frequency. The frequencies are changed to 1600 times per second, whereby the chances of interference and data loss are little. The procedure of frequency hopping can be simulated and tested with MATLAB, where it is possible to see the effects of modulation and coding of data passing through the channel with noises. By simulation it was recognized that the greatest impact on the errors are noises.

Проведен анализ недостатков существующих систем доведения информации до автономных необитаемых подводных аппаратов (АНПА). Предложена структура построения радиолинии КВ-диапазона для доведения информации до АНПА, находящегося в надводном положении. Произведена оценка эффективности функционирования радиолинии, а также рассмотрены требования к точности синхронизации приемо-передающих центров. Построены модели прогнозирования шкал синхронизации в среде Simulink., The disadvantages of existing systems of providing data to the autonomous unmanned underwater vehicles have been analysed. The structure for construction the radio communication at the range of short lengths waves for providing the data to the autonomous unmanned underwater vehicles on sea surface has been proposed. Efficiency of the radio communication operation has been assessed. Requirements of synchronization accuracy for the receiving and transmitting centers also have been considered. Models for forecasting the scales of synchronization have been developed at the Simulink

У роботі наводиться методика оцінки необхідної пропускної спроможності уніфікованого радіоканалу управління безпілотним літальним апаратом для штатного режиму роботи. Для виконання ним бойових задач пропонується використання широкосмугових сигналів з використанням технологій ФМ-ПВП, ППРЧ чи OFDM. The paper is induced the method of estimating the required bandwidth of unified radio channel control of unmanned aerial vehicle for normal operation. To carry out combat missions provided the use of wideband signals using technology PM-PRS, FHSS or OFDM. В работе наводится методика оценки необходимой пропускной способности унифицированного радиоканала управления беспилотным летательным аппаратом для штатного режима работы. Для выполнения им боевых задач предлагается использование широкополосных сигналов с использованием технологий ФМ-ПСП, ППРЧ или OFDM.

Currently, wireless communication technologies are expected to be widely employed for in-vehicle communication where in-vehicle communication is built upon the interactions of different parts inside the vehicle. This communication is to enable a variety of applications for driver and passenger needs. To have improved driving assistance, development of in-vehicle applications is very much needed. At present, intelligent systems inside the vehicle are mostly dominated by the wired technologies. The possibilities of wireless communication have inspired us and made an opportunity to analyse replacements for wired communication within a vehicle. In this connection, the scope of our thesis is to define the in-vehicle applications which are preferred by the wireless technologies, to define the applications using wired technologies which could be replaced by the wireless technologies and to identify those applications which are difficult to implement by the wireless technologies. In-vehicle wired networks; and problems of these wired networks, along with several existing applications, have been discussed at the initial stage of this thesis for the purpose of having a clear understanding. After that, existing In-vehicle wireless applications and several challenging applications have also been studied. Studies have been done on the most important wireless technologies with their respective specifications. The requirement of establishing wireless communication has also been explained. Finally, an analysis has been done according to the requirements of the applications and verification of their possible reliance on the wireless technologies. In a brief, comparable studies have been done among the wireless technologies to assess their current and future fitness for In-vehicle applications. The thesis concludes with some recommendations regarding when wireless technologies might be suitable for some in-vehicle applications to replace the wired technologies.

Проведено дослідження характеристик існуючих засобів формування та обробки широкосмугових сигналів. Встановлено, що такі засоби характеризуються підвищеною складністю реалізації. Зроблено висновок про перспективність формування сигналів на основі випадкових процесів з керованими ймовірнісними характеристиками.