Browsing 2014/3 by Issue Date
Now showing items 1-20 of 26
-
An Extended Virtual Aperture Imaging Model for Through-the-wall Sensing and Its Environmental Parameters Estimation
(Společnost pro radioelektronické inženýrství, 2014-09)Through-the-wall imaging (TWI) radar has been given increasing attention in recent years. However, prior knowledge about environmental parameters, such as wall thickness and dielectric constant, and the standoff distance ... -
Near Sea-Surface Mobile Radiowave Propagation at 5 GHz: Measurements and Modeling
(Společnost pro radioelektronické inženýrství, 2014-09)Near sea-surface line-of-sight (LoS) radiowave propagation at 5 GHz was investigated through narrowband measurements in this paper. Results of the received signal strength with a transmission distance of up to 10 km were ... -
Three-Pole Tunable Filters with High Rejection using Mixed Quarter-Lambda and Asymmetric Half-Lambda Resonators
(Společnost pro radioelektronické inženýrství, 2014-09)A novel three-pole tunable bandpass filter using varactor-loaded quarter-wavelength combline and asym-metric half-wavelength resonators is proposed in this paper. A nearly constant 3-dB absolute bandwidth is 150 ± 13 MHz ... -
Performance of Cross-layer Design with Multiple Outdated Estimates in Multiuser MIMO System
(Společnost pro radioelektronické inženýrství, 2014-09)By combining adaptive modulation (AM) and automatic repeat request (ARQ) protocol as well as user scheduling, the cross-layer design scheme of multiuser MIMO system with imperfect feedback is presented, and multiple outdated ... -
Modeling the Flux-Charge Relation of Memristor with Neural Network of Smooth Hinge Functions
(Společnost pro radioelektronické inženýrství, 2014-09)The memristor was proposed to characterize the flux-charge relation. We propose the generalized flux-charge relation model of memristor with neural network of smooth hinge functions. There is effective identification ... -
Pattern Synthesis of Dual-band Shared Aperture Interleaved Linear Antenna Arrays
(Společnost pro radioelektronické inženýrství, 2014-09)This paper presents an approach to improve the efficiency of an array aperture by interleaving two different arrays in the same aperture area. Two sub-arrays working at different frequencies are interleaved in the same ... -
High Input Impedance Voltage-Mode Biquad Filter Using VD-DIBAs
(Společnost pro radioelektronické inženýrství, 2014-09)This paper deals with a single-input multiple-output biquadratic filter providing three functions (low-pass, high-pass and band-pass) based on voltage differencing differential input buffered amplifier (VD-DIBA). The quality ... -
Single-, Dual- and Triple-band Frequency Reconfigurable Antenna
(Společnost pro radioelektronické inženýrství, 2014-09)The paper presents a frequency reconfigurable slot dipole antenna. The antenna is capable of being switched between single-band, dual-band or triple-band operation. The antenna incorporates three pairs of pin-diodes which ... -
The Impact of Interference on GNSS Receiver Observables – A Running Digital Sum Based Simple Jammer Detector
(Společnost pro radioelektronické inženýrství, 2014-09)A GNSS-based navigation system relies on externally received information via a space-based Radio Frequency (RF) link. This poses susceptibility to RF Interference (RFI) and may initiate failure states ranging from degraded ... -
On the Comparative Performance Analysis of Turbo-Coded Non-Ideal Sigle-Carrier and Multi-Carrier Waveforms over Wideband Vogler-Hoffmeyer HF Channels
(Společnost pro radioelektronické inženýrství, 2014-09)The purpose of this paper is to compare the turbo-coded Orthogonal Frequency Division Multiplexing (OFDM) and turbo-coded Single Carrier Frequency Domain Equalization (SC-FDE) systems under the effects of Carrier Frequency ... -
Modeling of Luneburg Lenses With the Use of Integral Equation Macromodels
(Společnost pro radioelektronické inženýrství, 2014-09)The so-called integral equation macromodel allowing to efficiently include Luneburg lens in the body-of-revolution method-of-moments (BoR-MoM) computational scheme is described. In the process of the macromodel construction, ... -
Research on Channel Estimation and OFDM Signals Detection in Rapidly Time-Variant Channels
(Společnost pro radioelektronické inženýrství, 2014-09)It is well known that iterative channel estimation and OFDM signals detection can significantly improve the performance of communication system. However, its performance is poor due to the modelling error of basis expansion ... -
Maximum Bandwidth Enhancement of Current Mirror using Series-Resistor and Dynamic Body Bias Technique
(Společnost pro radioelektronické inženýrství, 2014-09)This paper introduces a new approach for enhancing the bandwidth of a low voltage CMOS current mirror. The proposed approach is based on utilizing body effect in a MOS transistor by connecting its gate and bulk terminals ... -
Bounds on Minimum Energy per Bit for Optical Wireless Relay Channels
(Společnost pro radioelektronické inženýrství, 2014-09)An optical wireless relay channel (OWRC) is the classical three node network consisting of source, re- lay and destination nodes with optical wireless connectivity. The channel law is assumed Gaussian. This paper studies ... -
Low Complexity Noncoherent Iterative Detector for Continuous Phase Modulation Systems
(Společnost pro radioelektronické inženýrství, 2014-09)This paper focuses on the noncoherent iterative detection of continuous phase modulation. A class of simplified receivers based on Principal-Component-Analysis (PCA) and Exponential-Window (EW) is developed. The proposed ... -
Optimization of Filter by using Support Vector Regression Machine with Cuckoo Search Algorithm
(Společnost pro radioelektronické inženýrství, 2014-09)Herein, a new methodology using a 3D Electromagnetic (EM) simulator-based Support Vector Regression Machine (SVRM) models of base elements is presented for band-pass filter (BPF) design. SVRM models of elements, which are ... -
Analysis of Energy Consumption Performance towards Optimal Radioplanning of Wireless Sensor Networks in Heterogeneous Indoor Environments
(Společnost pro radioelektronické inženýrství, 2014-09)In this paper the impact of complex indoor environment in the deployment and energy consumption of a wireless sensor network infrastructure is analyzed. The variable nature of the radio channel is analyzed by means of ... -
Space-time Characteristics and Experimental Analysis of Broadening First-order Sea Clutter in HF Hybrid Sky-surface Wave Radar
(Společnost pro radioelektronické inženýrství, 2014-09)In high frequency (HF) hybrid sky-surface wave radar, the first-order sea clutter broadening is very complex and serious under the influence of ionosphere and bistatic angle, which affects the detection of ship target. ... -
Data Transparent and Polarization Insensitive All-Optical Switch based on Fibers with Enhanced Nonlinearity
(Společnost pro radioelektronické inženýrství, 2014-09)We have developed a data transparent optical packet switch prototype employing wavelength conversion based on four-wave mixing. The switch is composed of an electro-optical control unit and an all-optical switching segment. ... -
A Systematic Search for New Coupling Schemes of Cross-Coupled Resonator Bandpass Filters
(Společnost pro radioelektronické inženýrství, 2014-09)In this paper, a systematic approach to an extensive search for topologies of cross-coupled filters with generalized Chebyshev response is presented. The technique applies graph theory to find unique, nonisomorphic filter ...