Browsing 2012/4 by Issue Date
Now showing items 1-20 of 45
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3-D Microwave Imaging for Breast Cancer
(Společnost pro radioelektronické inženýrství, 2012-12)We introduce a novel microwave imaging technique for breast cancer detection. Our approach provides a one-pass inverse image solution, which is completely new and unprecedented, unrelated to tomography or radar-based ... -
Impedance Bandwidth and Gain Improvement for Microstrip Antenna Using Metamaterials
(Společnost pro radioelektronické inženýrství, 2012-12)An improved ultra-wideband (UWB) and high gain rectangular antenna is specifically designed in this paper using planar-patterned metamaterial concepts. The antenna has isolated triangle gaps and crossed gaps etched on the ... -
A Novel OFDM/DQPSK Receiver with Adaptive Remodulation Filter
(Společnost pro radioelektronické inženýrství, 2012-12)The description and performance analysis of a new OFDM/DQPSK signal receiver is considered in this paper. The proposed receiver has performance that is close to the performance for the coherent detection of the OFDM/DQPSK ... -
Analysis of Multipath Mitigation Techniques with Land Mobile Satellite Channel Model
(Společnost pro radioelektronické inženýrství, 2012-12)Multipath is undesirable for Global Navigation Satellite System (GNSS) receivers, since the reception of multipath can create a significant distortion to the shape of the correlation function leading to an error in the ... -
Radiation Characteristics of Tunable Graphennas in the Terahertz Band
(Společnost pro radioelektronické inženýrství, 2012-12)Graphene-enabled wireless communications constitute a novel paradigm which has been proposed to implement wireless communications among nanosystems. Indeed, graphene-based plasmonic nano-antennas, or graphennas, just a few ... -
Short-term Prediction and Detection of Dynamic Atmospheric Effects by Microwave Radiometer
(Společnost pro radioelektronické inženýrství, 2012-12)Specific utilization of a microwave radiometer for online monitoring, detection and, especially, prediction of particular dynamic atmospheric effects such as precipitation and cloudiness is proposed in the paper. The ... -
Utility based Dynamic Subcarrier Allocation for QoS Guarantees in SC-FMDA System
(Společnost pro radioelektronické inženýrství, 2012-12)Two utility based dynamic subcarrier allocation (DSA) algorithms: the max exponential utility (MEU) algorithm and the max weighted exponential utility (MWEU) algorithm are proposed for quality of service (QoS) guarantees ... -
Tunable Versatile High Input Impedance Voltage-Mode Universal Biquadratic Filter Based on DDCCs
(Společnost pro radioelektronické inženýrství, 2012-12)A high input impedance voltage-mode universal biquadratic filter with three input terminals and seven output terminals is presented. The proposed circuit uses three differential difference current conveyors (DDCCs), four ... -
Comparison of Planar Fractal Filters on Defected Ground Substrate
(Společnost pro radioelektronické inženýrství, 2012-12)The paper discusses approaches to the reduction of dimensions of planar filters (microstrip ones and coplanar ones). Filter dimensions are reduced by applying the fractal theory to the geometry of a filter, and by the ... -
Novel Feedback Calculation Technique for Improved Transmit Scheme
(Společnost pro radioelektronické inženýrství, 2012-12)Extended balanced space-time block coding (EBSTBC) is able to achieve large coding gain and guarantee full diversity for any number of transmit antennas. Performance of the EBSTBC has been improved with improved transmit ... -
Small Footprint Multilayered Millimeter-Wave Antennas and Feeding Networks for Multi-Dimensional Scanning and High-Density Integrated Systems
(Společnost pro radioelektronické inženýrství, 2012-12)This paper overviews the state-of-the-art of substrate integrated waveguide (SIW) techniques in the design and realization of innovative low-cost, low-profile and low-loss (L3) millimeter-wave antenna elements, feeding ... -
A Novel Method for Radio Propagation Simulation Based on Automatic 3D Environment Reconstruction
(Společnost pro radioelektronické inženýrství, 2012-12)In this paper, a novel method to simulate radio propagation is presented. The method consists of two steps: automatic 3D scenario reconstruction and propagation modeling. For 3D reconstruction, a machine learning algorithm ... -
Indoor Wireless RF Energy Transfer for Powering Wireless Sensors
(Společnost pro radioelektronické inženýrství, 2012-12)For powering wireless sensors in buildings, rechargeable batteries may be used. These batteries will be recharged remotely by dedicated RF sources. Far-field RF energy transport is known to suffer from path loss and therefore ... -
Empirical Modeling of Ducting Effects on a Mobile Microwave Link Over a Sea Surface
(Společnost pro radioelektronické inženýrství, 2012-12)In this paper, signal enhancement due to the ducts over a sea surface is experimentally investigated and modeled. The investigation is carried out through the study of air-to-ground mobile microwave links over a tropical ... -
Linear-Combined-Code-Based Unambiguous Code Discriminator Design for Multipath Mitigation in GNSS Receivers
(Společnost pro radioelektronické inženýrství, 2012-12)Unambiguous tracking and multipath mitigation for Binary Offset Carrier (BOC) signals are two important requirements of modern Global Navigation Satellite Systems (GNSS) receivers. A GNSS discriminator design method based ... -
Design, Fabrication and Properties of the Multimode Polymer Planar 1 x 2 Y Optical Splitter
(Společnost pro radioelektronické inženýrství, 2012-12)We report about design, fabrication and measurement of the properties of multimode 1 x 2 optical planar power splitter. The splitters were designed with help of OptiCAD software using ray tracing method. The dimensions of ... -
Impact of Power Allocation and Antenna Directivity in the Capacity of a Multiuser Cognitive Ad Hoc Network
(Společnost pro radioelektronické inženýrství, 2012-12)This paper studies the benefits that power control and antenna directivity can bring to the capacity of a multiuser cognitive radio network. The main objective is to optimize the secondary network sum rate under the capacity ... -
Retrodirective Antenna Array Using High Frequency Offset
(Společnost pro radioelektronické inženýrství, 2012-12)The paper deals with the design of a simple retrodirective antenna array exhibiting by high frequency offset between received and transmitted wave. Analysis of the beam pointing error using antenna array model developed ... -
The Distribution of Minimum of Ratios of Two Random Variables and Its Application in Analysis of Multi-hop Systems
(Společnost pro radioelektronické inženýrství, 2012-12)The distributions of random variables are of interest in many areas of science. In this paper, ascertaining on the importance of multi-hop transmission in contemporary wireless communications systems operating over fading ... -
Broadband Spectrum Survey Measurements for Cognitive Radio Applications
(Společnost pro radioelektronické inženýrství, 2012-12)It is well known that the existing spectrum licensing system results in a gross under-utilization of the frequency spectrum. Spectrum background measurements – spectrum surveys – provide useful data for spectrum regulation, ...