Procházení 2010/4 dle data publikování
Zobrazují se záznamy 1-20 z 39
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Controlling the Short-Range Propagation Environment Using Active Frequency Selective Surfaces
(Společnost pro radioelektronické inženýrství, 2010-12)This paper deals with a new approach to the control of the propagation environment in indoor scenarios using intelligent walls. The intelligent wall is a conventional wall situated inside a building, but equipped with an ... -
Sierpinski-Based Conical Monopole Antenna
(Společnost pro radioelektronické inženýrství, 2010-12)Planar Sierpinski monopole exhibits a multi-band behavior, but its parameters in operation frequency bands are not optimal. By mapping the Sierpinski monopole on a conical surface, a symmetrical three-dimensional (3-D) ... -
LMS Based Adaptive Channel Estimation for LTE Uplink
(Společnost pro radioelektronické inženýrství, 2010-12)In this paper, a variable step size based least mean squares (LMS) channel estimation (CE) algorithm is presented for a single carrier frequency division multiple access(SC-FDMA) system under the umbrella of the long term ... -
Simulation and Measurement of the Transmission Distortions of the Digital Television DVB-T/H Part 3: Transmission in Fading Channels
(Společnost pro radioelektronické inženýrství, 2010-12)The paper deals with the third (and last) part of results of the Czech Science Foundation research project that was aimed into the simulation and measurement of the transmission distortions of the digital terrestrial ... -
On the Effect of Channel Impairments on VANETs Performance
(Společnost pro radioelektronické inženýrství, 2010-12)The primary means of studying the performance of vehicular ad hoc networks (VANETs) are computer simulations. Nowadays, the development of analytical models and the use of hybrid simulations that combine analytical modeling ... -
Log-Polar Quantizer with the Embedded G.711 Codec
(Společnost pro radioelektronické inženýrství, 2010-12)In this paper a new two-dimensional vector quantizer for memoryless Gaussian source, realized in polar coordinates, is proposed. The G.711 codec is embedded in our vector quantizer, and therefore our vector quantizer is ... -
Optimum Detection Location-Based Cooperative Spectrum Sensing in Cognitive Radio
(Společnost pro radioelektronické inženýrství, 2010-12)Cognitive radio arises as a hot research issue in wireless communications recently, attributed to its capability of enhancing spectral efficiency and catering for the growing demand for bandwidth. As a good embodiment of ... -
Estimation of the Radio Channel Parameters using the SAGE Algorithm
(Společnost pro radioelektronické inženýrství, 2010-12)This paper presents the problem of estimating the parameters of a given number of superimposed signals, as is the case of the received signal in wireless communications. Based on the description of the received signal in ... -
Optimization of the Gaussian Kernel Extended by Binary Morphology for Text Line Segmentation
(Společnost pro radioelektronické inženýrství, 2010-12)In this paper, an approach for text line segmentation by algorithm with the implementation of the Gaussian kernel is presented. As a result of algorithm, the growing area around text is exploited for text line segmentation. ... -
Modular Filter Structures Using Current Feedback Operational Amplifiers
(Společnost pro radioelektronické inženýrství, 2010-12)The concept of the wave filtering is followed in the derivation of high-order filter topologies by employing Current Feedback Operational Amplifiers as active blocks. For this purpose, the wave equivalent of an appropriate ... -
Distributed Multi-Commodity Network Flow Algorithm for Energy Optimal Routing in Wireless Sensor Networks.
(Společnost pro radioelektronické inženýrství, 2010-12)This work proposes a distributed algorithm for energy optimal routing in a wireless sensor network. The routing problem is described as a mathematical problem by the minimum-cost multi-commodity network flow problem. Due ... -
Sensing Task Allocation for Heterogeneous Channels in Cooperative Spectrum Sensing
(Společnost pro radioelektronické inženýrství, 2010-12)In the traditional centralized cooperative spectrum sensing, all secondary users sense the same channel. But, for a given channel, there exists detection performance diversity among all the users, due to the different ... -
Compensation-based Game for Spectrum Sharing in the Gaussian Interference Channel
(Společnost pro radioelektronické inženýrství, 2010-12)This paper considers an optimization problem of sum-rate in the Gaussian frequency-selective channel. We construct a competitive game with an asymptotically optimal compensation to approximate the optimization problem of ... -
New Squarer Circuits and a Current-Mode Full-Wave Rectifier Topology Suitable for Integration
(Společnost pro radioelektronické inženýrství, 2010-12)In this paper, three squarer configurations and a current-mode (CM) full-wave rectifier circuit are suggested. The first and second squarer configurations respectively use two PMOS and two NMOS transistors while the third ... -
Key Information Retrieval in Hyperspectral Imagery through Spatial-Spectral Data Fusion
(Společnost pro radioelektronické inženýrství, 2010-12)Hyperspectral (HS) imaging is measuring the radiance of materials within each pixel area at a large number of contiguous spectral wavelength bands. The key spatial information such as small targets and border lines are ... -
Design of Polymer Wavelength Splitter 1310 nm/1550 nm Based on Multimode Interferences
(Společnost pro radioelektronické inženýrství, 2010-12)We report about design of 1x2 1310/1550 nm optical wavelength division multiplexer based on polymer waveguides. The polymer splitter was designed by using RSoft software based on beam propagation method. Epoxy novolak resin ... -
Improvement of RF Vector Modulator Performance by Feed-forward Based Calibration
(Společnost pro radioelektronické inženýrství, 2010-12)RF Vector Modulator enables independent control of a narrowband RF signal amplitude and phase. Unfortunately practical realization of an analog vector modulator suffers from misbalances and imperfections in the I and Q ... -
Investigating the Behavior of Compact Composite Descriptors in Early Fusion, Late Fusion and Distributed Image Retrieval
(Společnost pro radioelektronické inženýrství, 2010-12)In Content-Based Image Retrieval (CBIR) systems, the visual content of the images is mapped into a new space named the feature space. The features that are chosen must be discriminative and sufficient for the description ... -
Behavioral Modeling of a C-Band Ring Hybrid Coupler Using Artificial Neural Networks
(Společnost pro radioelektronické inženýrství, 2010-12)Artificial Neural Networks (ANNs) gained importance on the RF microwave (MW) design area and behavioral modeling of MW components in the past few decades. This paper presents a cost effective neural network (NN) approach ... -
An Energy Efficient MAC Protocol for QoS Provisioning in Cognitive Radio Ad Hoc Networks
(Společnost pro radioelektronické inženýrství, 2010-12)The explosive growth in the use of real-time applications on mobile devices has resulted in new challenges to the design of medium access control (MAC) protocols for ad hoc networks. In this paper, we propose an energy ...