A NEW LOOK AT THE INVESTMENT STRATEGY FOR THE FSS PROVIDER
The article is carried out the analysis of investment attractiveness of satellite operators and industry prospects in the future. It is shown that operators are forced to change the system of monetization of its services.
Keywords: fixed-satellite service (FSS), market conjuncture, HTS, development prospects.
STUDY OF EFFECTIVENESS USING SHORT LDPC CODES IN SATELLITE TELECOMMUNICATION SYSTEMS
Considered options and ways to improvement of uplink channels in satellite telecommunication systems, including the use of short LDPC codes. Given the features of construction short LDPC codes, namely the search for 4-cycles and 6-cycles in the parity-check matrix, which allows to increase the energy gain of more than 0.5 dB when error probability less 10-4. Selected optimal options parity-check matrices for short LDPC codes (128,64), (256,128) and (512, 256). Simulations showed that short LDPC codes exhibit significant coding gain compared to BCH codes and can be used in future satellite communication systems. Code (512, 256) allows to obtain the energy gain of about 1 dB compared to the code (256,128), which yields the same payoff before the code (128,64).
Keywords: parity-check matrices, LDPC, data-driven interaction, telecommunication systems.
THE USE OF MEASUREMENTS ON INITIAL FREQUENCIES IN GNSS PRECISE POINT POSITIONING
A.A. Povalyaev, Moscow Aviation Institute (NRU), professor, JSC «Russian Space Systems», Dr.Sci.(Tech.); firstname.lastname@example.org
A.N. Podkorytov, Moscow Aviation Institute (NRU), docent, JSC «Russian Space Systems», Ph.D.; email@example.com
Ambiguity resolution of phase measurements in global navigation satellite systems (GNSS) is implemented for Precise Point Positioning in the article. Taking into account underlying feature of design matrix in singular system of GNSS equations algebraic details of rank deficiency resolving for this task are considered. Observation models on GPS and GLONASS initial frequencies are proposed and investigated. Specific feature of GLONASS observation model connected with frequency division multiple access is described. To exclude influence of ionosphere delays to the estimates of user coordinates for observation models on GPS and GLONASS initial frequencies original filtering method is applied. Obtained results show that efficiency of precise point positioning for GPS observations is significantly increased due to ambiguity resolution. Preliminary results for GLONASS system are shown. The study contains comparison of decoupled satellite clocks produced with global and local network and analysis of GPS and GLONASS positioning quality for Precise Point Positioning with ambiguity resolution.
Keywords: GNSS, Integer PPP, Float PPP, ambiguity resolution.
COEFFICIENTS OF JAMMING TO UNIT OF DETECTION AND TRACKING NAVIGATION SIGNALS OF NAVIGATION EQUIPMENT OF SATELLITE RADIONAVIGATION SYSTEM
The development of satellite radionavigation systems and the extension of their application in the military sphere actualizes the issues related to countering these systems. There are specific requirements to interference immunity of navigation equipment under conditions of intentional interferences. Coefficient of jamming is the most important characteristic of an interference immunity of navigation equipment. In this article we propose the method of determining of jamming coefficients of the functions of detection and tracking of navigation signals, which are implemented during the operation of consumer navigation equipment for various indices of jamming quality.
Keywords: satellite radionavigation system, jamming, coefficients of jamming, noise interference, interference immunity.
INVESTIGATION OF CHARACTERISTICS OF SPACECRAFTS' DIRECTIONAL ONBOARD ANTENNAS IN THE EARLY STAGES OF DESIGN
E.V. Ovchinnikova, Moscow Aviation Institute (NRU), associate professor, Ph.D.; firstname.lastname@example.org
P.A. Smachilin, Moscow Aviation Institute (NRU), associate professor, Ph.D.; email@example.com
S.G. Kondratjeva, Moscow Aviation Institute (NRU), associate professor, Ph.D.; firstname.lastname@example.org
E.V. Gadzhiev, Moscow Aviation Institute (NRU), department of radiophysics, antenna and microwave technique, postgraduate student; email@example.com
The article is focused on computer-aided design (CAD) antennas and microwave devices. Through the use of CAD for electrodynamic simulation, developers of antennas and microwave devices have the opportunity not only to speed up the development process, but also to solve more complex problems. The presence of a number of CAD and their interaction with external programs can solve the tasks using different methods. There is also a series of numerical methods for solving Maxwell’s equations in the frequency domain and time domain.
The main purpose of this article is to show the advantage of using CAD in the design of antennas and microwave devices.
Keywords: computer-aided design, Maxwell’s equations, onboard antennas, spacecraft, antenna array.
THE QUASI-COHERENT BPSK SIGNAL DEMODULATOR BASED ON THE GLSS SYNCHRONIZATION SYSTEM
The article presents the results of the research of the innovative quasi-coherent BPSK demodulator structure based on the Globally Linearized Synchronization System (GLSS). The structure of the BPSK-GLSS demodulator and formulas for calculating the time of frequency synchronization for the GLSS system are given. The results of the investigation of BPSK-GLSS demodulator in MATLAB / Simulink simulation environment are shown.
Keywords: quasi-coherent demodulator, BPSK modulation, synchronization time, noise immunity, simulation.
DEVELOPMENT OF MEASUREMENT ALGORITHM SPEED OF THE VEHICLE USING THE CAR’S PANORAMIC RADAR
Bui Chi Thanh, Moscow Aviation Institute (NRU), postgraduate student, department 407; firstname.lastname@example.org
D.V. Маrin, Moscow Aviation Institute (NRU), postgraduate student, department 407; email@example.com
V.V. Rastorguev, Moscow Aviation Institute (NRU), professor, Ph.D.; firstname.lastname@example.org
Algorithm for estimation of horizontal component of velocity vector of vehicle is considered in the paper. The using of cross-correlation function of adjacent radar images is proposed to produce the speed estimation. The results of formation and analyzing cross-correlation function between adjacent radar images are presented. The parameters of the cross-correlation function (maximum, width, number of maximums) which were received as a result of radar images processing, were analyzed. It is concluded that this function can be used as a tool for estimation of horizontal component of velocity vector of vehicles.
Keywords: automotive radar, radar image, cross-correlation function, measurement of the velocity vector.
MODELLING OF AIRCRAFT MOVEMENTS AND THE SURROUNDING ENVIRONMENT VISUALIZATION DURING APPROACH AND LANDING OPERATIONS
A.V. Kartukov, Moscow Aviation Institute (NRU), department of radio receivers, senior lecturer; email@example.com
G.V. Merkishin, Moscow Aviation Institute (NRU), head of the department of radio receivers, professor; firstname.lastname@example.org
I.L. Prudnikov, Moscow Aviation Institute (NRU), department of radio receivers, graduate student; email@example.com
One of the most complex and demanding phases of flight is the landing of the aircraft, especially in bad weather. Today there are a number of landing systems, to varying degrees simplify the planting process. Some of these systems require a software analysis of the situation during the flight, and the pilot’s notification on the implementation of the landing stages. To visualize the three-dimensional paintings, aimed at reducing the emotional load, the program simulation of the aircraft movement was developed.
Keywords: landing system, modeling of three-dimensional images, psycho-emotional load.
REDUCTION OF HANDOVER PROBABILITY IN CELLULAR COMMUNICATIONS SYSTEMS WITH CAPACITY TRANSFER
Present article is dedicated to evaluation of the effect of reducing handover impact on the cellular communications system performance when capacity transfer technology is applied. Handover procedure is creating an additional load on signaling channels of cellular communications system, resulting in a number of negative effects. The use of the cellular communications system with capacity transfer reduces probability of inter-cell handovers, reducing load on communication channels, improving quality and reliability of communications. The comparison of inter-cell handover probability for different network configurations of standard cellular communications system and cellular communications system with capacity transfer is carried out in the article. Significant gain in reducing of the inter-cell handover probability in 2−4 times is shown for cellular communications system with capacity transfer, depending on the considered topology.
Keywords: cellular communications, system with capacity transfer, handover.