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Methods for attitude & orbit control of the information satellites with economical expending of the energy and fuel onboard resources are presented. We consider the land-survey mini-satellites with an orbit altitude from 600 up to 800 km when their lifetime must be up to 10 years and economical control is actual problem.
This paper proposes a fuzzy interval type 2 logic based autonomous lateral flight controller for UAVs (unmanned aerial vehicles). The implementation framework utilizes MAT-LAB's standard configuration and the Aerosim Aeronautical Simulation Block Set which provides a complete set of tools for rapid development of detailed 6 degree-of-freedom nonlinear generic manned/unmanned aerial vehicle models...
The paper deals with the robust algorithm for consensus control of dynamical networks where each local subsystem is described by nonlinear differential equation with delay, unknown parameters and disturbances. The algorithm provides the network synchronization and compensates uncontrollable disturbances with a given accuracy. Analytical results are presented by network consisting of four nodes.
The algorithm of the interval observer design for a class of nonlinear systems with parametric uncertainty is considered. It is shown that the observer allows to derive an interval that contains the actual value of the state at a given time. The main condition of such a device construction deals with a cooperativity of the interval estimation error dynamics. The question of the selecting the individual...
In the past, fingerprinting algorithms have been suggested as a practical and cost-effective means for deploying localisation services. Previous research, however, often assumes an (idealised) laboratory environment rather than a realistic set-up. In our work we analyse challenges occurring from a university environment which is characterised by hundreds of access points deployed and by heterogeneous...
In this paper we introduce an adaptive channel estimation scheme for two-way relay with node capability. The adaptive filter used is called Block Fast Array Multichannel 2D-Recursive Least Square (BFAM 2D-RLS). The modulation used is Orthogonal Frequency Division Multiplexing (OFDM) and channel estimation is done in the frequency domain. The proposed channel estimator considers correlation of channel...
Analysis of the infinite-server queueing system with semi-Markov arrivals is presented in the paper. The analysis is performed under an asymptotic condition of input rate infinite growth. It is shown that the stationary probability distribution of the number of customers in the system can be approximated by Gaussian distribution when the input rate is great enough. Parameters of the approximation...
We consider a two-channel queuing system with unreliable servers which fail alternately for modeling of hybrid communication systems, which have a millimeter-wave (71–76 GHz, 81–86 GHz) radio channel as a backup communication channel. The stationary distribution of the system states and the most important performance characteristics were obtained.
An iterative low-complexity channel estimation algorithm for OFDM signals in frequency domain is presented. Algorithm uses initial channel estimation based on pilot subcarriers, 1-D adaptive Wiener filtering in the time direction and Maximum a-posteriori probability (MAP) estimation that uses both pilot and weighted data subcarriers. The final step is the simplified version of an iterative Expectation-Maximization...
The models of peer to peer protocols are presented with the help of one-step processes. On the basis of this presentation and the method of randomization of one-step processes, it is described method for constructing models of peer to peer protocols. The models of FastTrack and Bittorrent protocols are studied by means of proposed method.
Interference Alignment (IA) is a rather new technique to achieve higher Degrees-of-Freedom (DoF) compared to traditional orthogonal naive methods, like, Time Division Multiple Access (TDMA). In many IA schemes, Instantaneous Channel State Information at Transmitter (CSIT) is mandatory. However, this requirement becomes an obstacle to implement those methods in practice. In some practical scenarios,...
In this paper, we consider the operation of a mobile multi-radio wireless device, which may simultaneously utilize several radio access technologies when transmitting its data. Whereas the use of multiple radios does improve network capacity and user connectivity experience, it also results in a significant growth of device energy demands. To compensate for it, the device may leverage the excess availability...
We propose a differential space-time coded (STC) radio-frequency-identification (RFID) system where the tag has two antennas and the reader has a single or multiple antennas. In this system, the M-ary phase-shift keying constellation is used, and encoding at the tag and decoding at the reader are simple. Simulation results show that the proposed STC RFID system can achieve a performance improvement...
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