Display probability of symbol errors for MQAM on Rician fading channel based on MGF method

We present a new method for calculating the probability of error per symbol (Symbol Error Probability, SEP) of M-ary Quadrature Amplitude Modulation (MQAM) over a slow, flat, identically independently distributed Rician fading channels. Since fading is one of the major constraints in wireless communications, the diversity modulation technique is used for the efficient transfer of message signals. Exact analysis of error probability per symbol for MQAM, transmitted over Rician fading channels, is performed by N branches of diversity reception using maximum ratio of signal-to-noise power (maximal-ratio-combining, MRC), where the information in the channel on the receiver side is known. We also analyzed the performances of MQAM over Rician fading channels are here also analyzed. Approximate formula is used to represent SEP for MQAM transmitted over Gaussian channels. Boundary condition for the approximation is M≥4 and 0≤SNR≤30 dB

A Proposed Method for Determining Propulsion Coefficient Based on Testing Motor Freighters on Danube Waterway Network

The paper presents a proposal of mathematical models for the determination of propulsion coefficient, eta pp, intended for the analysis of motor freighters applied on the river watercourses. As the main paper contribution three different model types are developed, depending on the variable which contributes to eta pp value. These variables are: 1. the freighter sailing velocity, (nu); 2. the installed capacity of the main drive motor of outboard unit, (N-inst); 3. the combination of these two variables, (N-inst, nu). The models are verified on the examples of several motor freighters which are applied at Danube river. The special attention is paid to the determination of the optimum approximation function in each case. In all three cases it is a quadratic function. The correlation coefficient for the comparison in all analyzed examples is higher than 0.87, being even higher than 0.99 for the first model

Maximum electric field estimation in the vicinity of 5G base stations before their start-up

Introduction/purpose: This paper presents initial development of the procedure for electric field estimation in the vicinity of 5G base stations. Methods: The procedure allows determination of future radiation levels before traffic is established over applied antenna systems on the basis of measured values of electric field levels caused by the signal forming Synchronization Signal Block. It is possible to perform necessary calculations for a very accurate estimation even if some important parameters of the radiation characteristics (such as the frequency span between the frequency carriers on the radio interface) are not a priori known. In this way, communication with mobile system operators before measurement is significantly simplified because operators do not need to know system technical details. Results: The developed formula for electric field estimation is verified comparing the calculated values by its implementation to the practical results obtained by intensive measurements on a great number of 5G base stations in a highly developed country. The formula gives a pessimistic result, i.e. a higher electric field level than it is obtained by all such performed measurements. Conclusion: This estimation allows mobile system operators to predict whether the electromagnetic field around base stations could be dangerous for human health when systems come to full operation while considering national and international recommendations dealing with radiation levels

COMB JAMMING AS A STRATEGY FOR RCIED ACTIVATION PREVENTION

The main objective of this paper is the analysis of comb jamming as a technique for RCIED activation prevention. Presentation of three strategies for comb signal generation follows after comprehensive survey of various jamming techniques in the introduction. There are two paper original contributions. The first one is quantitative comparison for three signal generation techniques of their emission power in relation to barrage jamming under the condition of equal BER value. The second contribution is determination of exact BER value as a function of emission power in the case of barrage jamming. Until now we have made different analyses and comparisons starting from estimated emission power. The analysis procedure is performed for QPSK modulated RCIED activation signal. Power saving is evident for all three methods of jamming signal generation. It is proved that additional 2.5dB of power saving is achieved by equalization of frequency components level in comb signal. The analysis in this paper shows that comb jamming allows the same effects as barrage jamming, but with lower emission power

Display probability of symbol errors for MQAM on Rician fading channel based on MGF method

We present a new method for calculating the probability of error per symbol (Symbol Error Probability, SEP) of M-ary Quadrature Amplitude Modulation (MQAM) over a slow, flat, identically independently distributed Rician fading channels. Since fading is one of the major constraints in wireless communications, the diversity modulation technique is used for the efficient transfer of message signals. Exact analysis of error probability per symbol for MQAM, transmitted over Rician fading channels, is performed by N branches of diversity reception using maximum ratio of signal-to-noise power (maximal-ratio-combining, MRC), where the information in the channel on the receiver side is known. We also analyzed the performances of MQAM over Rician fading channels are here also analyzed. Approximate formula is used to represent SEP for MQAM transmitted over Gaussian channels. Boundary condition for the approximation is M≥4 and 0≤SNR≤30 dB

A Proposed Method for Determining Propulsion Coefficient Based on Testing Motor Freighters on Danube Waterway Network

The paper presents a proposal of mathematical models for the determination of propulsion coefficient, eta pp, intended for the analysis of motor freighters applied on the river watercourses. As the main paper contribution three different model types are developed, depending on the variable which contributes to eta pp value. These variables are: 1. the freighter sailing velocity, (nu); 2. the installed capacity of the main drive motor of outboard unit, (N-inst); 3. the combination of these two variables, (N-inst, nu). The models are verified on the examples of several motor freighters which are applied at Danube river. The special attention is paid to the determination of the optimum approximation function in each case. In all three cases it is a quadratic function. The correlation coefficient for the comparison in all analyzed examples is higher than 0.87, being even higher than 0.99 for the first model

RELIABILITY ANALYSIS OF DIFFERENT RCIED ACTIVATION SIGNAL RESPONSIVE JAMMING TECHNIQUES AND THEIR COMPARISON TO ACTIVE JAMMING

In this paper we compared the time required for the successful jamming of remote controlled improvised explosive devices activation using active and responsive jamming methods. As a representative of active jamming method we analyzed jamming signal generation using frequency sweep. For the analysis of the possible activating signal presence based on responsive jamming procedures we first supposed Fast Fourier Transform (FFT) implementation and compared its analysis rate to the rate of sweep jamming. Taking into account the current technology state, it is proved that the time required to achieve the successful jamming relied on FFT analysis may be less than in the case of active sweep jamming. After that we considered pros and cons for energy detector and matched filter detector implementation in responsive jamming. For these two detector types it is shown how to determine the number of analysis blocks to achieve approximately the same number of collected samples as in the case of FFT implementation, starting from the probabilities of false detection and miss of detection

Primena telefarmacije - značaj uloge farmaceutskih tehničara

In this paper, the systems of telepharmacy services are presented considering several aspects. The first part considers the basic components of the telepharmacy systems. Examples of telepharmacy application in military services and, above all, in rural areas are presented. Then, the role of pharmacists and pharmacy technicians in telepharmacy systems is analyzed. In the second part, the importance of the role of technicians for quality execution of the telepharmacy program is proved by one illustrative, mathematical example, using the analysis of several system parameters.U ovom radu prikazani su sistemi telefarmaceutske usluge sa nekoliko aspekata. U prvom delu rada date su osnovne odrednice telefarmaceutskih sistema. Dati su primeri primene telefarmacije u vojnim službama i, pre svega, u ruralnim oblastima. Zatim je prikazana uloga farmaceuta i farmaceutskih tehničara u sistemima telefarmacije. U drugom delu jednim ilustrativnim matematičkim primerom prikazan je, analizom nekoliko parametara, značaj uloge tehničara za kvalitetno izvršavanje programa telefarmacije

VERIFICATION OF CALCULATION METHOD FOR DRONE MICRO-DOPPLER SIGNATURE ESTIMATION

Drones micro-Doppler signatures obtained by FMCW radars are an excellent procedure for malicious drone detection, identification and classification. There are a number of contributions dealing with recorded spectrograms with these micro-Doppler signatures, but very low number of them has analyzed possibility to calculate echo caused by drone moving parts. In this paper, starting from already existing mathematical apparatus, we presented such spectrograms as a function of changing drone moving parts characteristics: rotor number, blades number, blade length and rotor moving speed. This development is the part of a wider project intended to prevent malicious drone usage

Kontrola snage bazne stanice u GSM: utjecaj gustoće korisnika u stanici

In this paper is presented that base station output power can be decreased by the power control in each channel. In this case very important is the distribution function of users\u27 density in the cell. We present the examples of the cells without power control and the examples of the cells with power control, where the distribution of users\u27 density in the cell is of various types. Some results are compared to the results of measurements, and some to the results obtained by simulation.U radu se pokazuje da se izlazna snaga bazne stanice može smanjiti upravljanjem snage pojedinih kanala. U tom slučaju značajnu ulogu ima funkcija raspodjele gustoće korisnika u stanici. Dati su primjeri stanica bez upravljanja snagom i primjeri stanica s upravljanjem snagom gdje je raspodjela gustoće korisnika u stanici različitog tipa. Neki rezultati upoređeni su s rezultatima mjerenja, a neki sa simulacijskim rezultatima