Browsing 2010/1 by Issue Date
Now showing items 1-20 of 31
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FMCW Radar Performance for Atmospheric Measurements
(Společnost pro radioelektronické inženýrství, 2010-04)Frequency-modulated continuous-wave radars (FMCW) have been used in the investigation of the atmosphere since the late 1960’s. FMCW radars provide tremendous sensitivity and spatial resolution compared to their pulsed ... -
Comparison of Fuzzy Logic and Genetic Algorithm Based Admission Control Strategies for UMTS System
(Společnost pro radioelektronické inženýrství, 2010-04)CDMA systems have so-called soft capacity, so the total number of possible sessions has not an exact value. The capacity of CDMA system depends on the interference level in the system. There are therefore RRM (Radio Resources ... -
Multicriteria Optimization of Antennas in Time-Domain
(Společnost pro radioelektronické inženýrství, 2010-04)An original approach to the time-domain multicriteria optimization of antennas is presented. For a given excitation pulse, the time-domain objective function takes the “time-domain impedance matching”, distortion of responses ... -
Optical Fiber Distributed Sensing System Applied in Cement Concrete Commixture Research
(Společnost pro radioelektronické inženýrství, 2010-04)DTS are unique optical-fiber distributed systems for measuring of temperature or mechanical tension. These systems use non-linear properties of optical fibers. Optical fiber can therefore be used not only for telecommunication ... -
Feedback Compensation Algorithm for BPSK/QPSK Carrier Synchronization
(Společnost pro radioelektronické inženýrství, 2010-04)This paper deals with carrier synchronization problem in coherent communication system, such as BPSK and QPSK. First, this paper surveys and analyzes currently existing carrier synchronization algorithms and relevant ... -
Modeling of the Phase Noise in Space Communication Systems
(Společnost pro radioelektronické inženýrství, 2010-04)Our work is focused on the investigation of an influence of an additive thermal noise and a multiplicative phase noise in space communication chains. The most important properties of both noise types are summarized. The ... -
Blind Oversampling Data Recovery with Low Hardware Complexity
(Společnost pro radioelektronické inženýrství, 2010-04)The paper is focused on the optimization and implementation of fully digital feed-forward blind oversampling CDR (BO-CDR). Two new phase-decision algorithms are proposed. Their complexity is very low, enabling a very simple ... -
Minimum Configuration Insensitive Multifunctional Current-Mode Biquad Using Current Conveyors and All-Grounded Passive Components
(Společnost pro radioelektronické inženýrství, 2010-04)This paper proposes a new current conveyorbased high-output impedance single-input three-output current mode filter with minimum configuration. It contains two dual output second generation current conveyors, one third ... -
Calculation and Comparison of Turbulence Attenuation by Different Methods
(Společnost pro radioelektronické inženýrství, 2010-04)This paper is focused on the effect of turbulence in atmospheric transmission media. A short introduction of the origin of turbulent atmosphere is given. Two classical methods for the calculation of turbulence attenuation ... -
Modeling of Human Head Surface by Using Triangular B-Splines
(Společnost pro radioelektronické inženýrství, 2010-04)The paper deals with modeling of human head surface on the basis of quadratic triangular B-splines for the standard videocodec MPEG-4 SNHC. First, we define a triangular B-spline surface of any degree and then we present ... -
Use of Multi-Watermarking Schema to Maintain Awareness in a Teleneurology Diagnosis Platform
(Společnost pro radioelektronické inženýrství, 2010-04)Following the tremendous evolution of transferring images through the Internet, it is necessary to ensure security during this act, especially for medical images. The application of multiple watermarking tech- nique ... -
Simulation and Evaluation of CTP and Secure-CTP Protocols
(Společnost pro radioelektronické inženýrství, 2010-04)The paper discusses characteristics and qualities of two routing protocols – Collection Tree Protocol and its secure modification. The original protocol, as well as other protocols for wireless sensors, solves only problems ... -
The PAPR and Simple PAPR Reduction of the 2D Spreading Based Communication Systems
(Společnost pro radioelektronické inženýrství, 2010-04)This paper deals with Peak to Average Power Ra- tio (PAPR) characteristics and the theory of variable spread- ing factor orthogonal frequency and code division multiplex- ing (VSF-OFCDM) systems. Comparison and evaluation ... -
Estimating a Spectral Correlation Function under the Conditions of Imperfect Relation between Signal Frequencies and a Sampling Frequency
(Společnost pro radioelektronické inženýrství, 2010-04)This paper is devoted to the estimation of the spectral correlation function. The examined signal is a simple DSB-SC signal. The aim of the paper is discovering events connected with nonstandard relations between signal ... -
Performance of Data Services in Cellular CDMA in Presence of Soft Handoff and Packet Combining
(Společnost pro radioelektronické inženýrství, 2010-04)Performance analysis of data services is studied in CDMA network in presence of soft handoff (HO) and packet combining. Packet combining in conjunction with soft handoff is found to enhance throughput, reduce delay and ... -
A Robust Threshold for Iterative Channel Estimation in OFDM Systems
(Společnost pro radioelektronické inženýrství, 2010-04)A novel threshold computation method for pilot symbol assisted iterative channel estimation in OFDM systems is considered. As the bits are transmitted in packets, the proposed technique is based on calculating a particular ... -
A Color Image Watermarking Scheme Resistant against Geometrical Attacks
(Společnost pro radioelektronické inženýrství, 2010-04)The geometrical attacks are still a problem for many digital watermarking algorithms at present. In this paper, we propose a watermarking algorithm for color images resistant to geometrical distortions (rotation and scaling). ... -
Lossless Authentication Watermarking Based on Adaptive Modular Arithmetic
(Společnost pro radioelektronické inženýrství, 2010-04)Reversible watermarking schemes based on modulo-256 addition may cause annoying salt-and-pepper noise. To avoid the salt-and-pepper noise, a reversible watermarking scheme using human visual perception characteristics and ... -
Impact of Different Active-Speech-Ratios on PESQ’s Predictions in Case of Independent and Dependent Losses (in Presence of Receiver-Side Comfort-Noise)
(Společnost pro radioelektronické inženýrství, 2010-04)This paper deals with the investigation of PESQ’s behavior under independent and dependent loss conditions from an Active-Speech-Ratio perspective in presence of receiver-side comfort-noise. This reference signal characteristic ... -
Closed-form Description of Microwave Signal Attenuation in Cellular Systems
(Společnost pro radioelektronické inženýrství, 2010-04)The reliable and accurate description of signal attenuation characteristics is important in the simulation and performance analysis of wireless communications systems. Recent works have provided analytical expres- sions ...