Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of electromagnetic engineering and science
Journal Basic Information
Journal DOI :
The Korean Institute of Electromagnetic Engineering and Science
Editor in Chief :
Volume & Issues
Volume 12, Issue 4 - Dec 2012
Volume 12, Issue 3 - Sep 2012
Volume 12, Issue 2 - Jun 2012
Volume 12, Issue 1 - Mar 2012
Selecting the target year
PER Analysis for Cooperative Multi-Hop Transmission Protocol over Nakagami-m Fading Channels
Duy, Tran Trung ; Kong, Hyung-Yun ;
Journal of electromagnetic engineering and science, volume 12, issue 3, 2012, Pages 189~195
DOI : 10.5515/JKIEES.2012.12.3.189
In this paper, we propose a novel protocol called a Multi-hop Diversity Transmission protocol in which the retransmission is realized by a relay that is Nearest to a current Source (MDTNS). We derive the mathematical expressions of the packet error rate (PER) and the average number of transmissions over Nakagami-m fading channels, and verify them by Monte Carlo simulations. The simulation results show that the MDTNS protocol improves the performance of the network in terms of PER when compared to the Multi-hop Diversity Transmission protocol in which the retransmission is done by a relay that is Nearest to Destination (MDTND) and to the conventional multi-hop transmission (CMT) protocol.
Cooperative Spectrum Sensing Via Sequential Detection: A Method to Reduce the Sensing Time
Thanh, Truc Tran ; Kong, Hyung-Yun ;
Journal of electromagnetic engineering and science, volume 12, issue 3, 2012, Pages 196~202
DOI : 10.5515/JKIEES.2012.12.3.196
Spectrum sensing is one of the most important functions in cognitive radio systems. In this paper, we focus on reducing the sensing time in a cooperative spectrum sensing paradigm. In the proposed scheme, a sequential detection technique is employed to provide a robust and quick detection system. Each of the secondary users measures the log-likelihood probability of the received signals and then sequentially reports to the base station. Here, the maximum ratio combining (MRC) technique is employed to reduce the average sample number (ASN) in order to reduce the sensing time. This proposed scheme is analyzed and simulated to illustrate the performance in comparison with the other given methods. Analysis and simulation are provided to validate the proposed method.
Performance of Spiked Population Models for Spectrum Sensing
Le, Tan-Thanh ; Kong, Hyung-Yun ;
Journal of electromagnetic engineering and science, volume 12, issue 3, 2012, Pages 203~209
DOI : 10.5515/JKIEES.2012.12.3.203
In order to improve sensing performance when the noise variance is not known, this paper considers a so-called blind spectrum sensing technique that is based on eigenvalue models. In this paper, we employed the spiked population models in order to identify the miss detection probability. At first, we try to estimate the unknown noise variance based on the blind measurements at a secondary location. We then investigate the performance of detection, in terms of both theoretical and empirical aspects, after applying this estimated noise variance result. In addition, we study the effects of the number of SUs and the number of samples on the spectrum sensing performance.
An Enhanced Skirt Characteristics Triple-Mode Filter
Lee, Ja-Hyeon ; Nam, Hun ; Lim, Yeong-Seog ;
Journal of electromagnetic engineering and science, volume 12, issue 3, 2012, Pages 210~215
DOI : 10.5515/JKIEES.2012.12.3.210
This paper presents a compact microstrip triple-mode filter with enhanced skirt characteristics. The presented triple-mode filter configuration supports three transmission poles and three transmission zeros within the nearby passband. Two of transmission zeros are generated by a triple-mode resonator itself, and the third one is generated by small cross-couplings between the I/O ports. Each resonance condition and the transmission zero generation conditions are analyzed using an equivalent circuit. The bandpass filter is designed for a 2.4 GHz WLAN. The filter was fabricated with a relative dielectic constant of 3.5 and a thickness of 0.76 mm. The fabricated filter has a small size (
is guided wavelength at a center frequency) and shows high performing skirt characteristics.
An Eight-Way Radial Switch Based on SIW Power Divider
Lee, Dong-Mook ; An, Yong-Jun ; Yook, Jong-Gwan ;
Journal of electromagnetic engineering and science, volume 12, issue 3, 2012, Pages 216~222
DOI : 10.5515/JKIEES.2012.12.3.216
This paper presents a single-pole eight-throw switch, based on an eight-way power divider, using substrate integrate waveguide(SIW) technology. Eight sectorial-lines are formed by inserting radial slot-lines on the top plate of SIW power divider. Each sectorial-line can be controlled independently with high level of isolation. The switching is accomplished by altering the capacitance of the varactor on the line, which causes different input impedances to be seen at a central probe to each sectorial line. The proposed structure works as a switching circuit and an eight-way power divider depending on the bias condition. The change in resonant frequency and input impedance are estimated by adapting a tapered transmission line model. The detailed design, fabrication, and measurement are discussed.
Hybrid Synchronization Scheme for Multi-Carrier Communication Systems
Kim, Eung-Sun ; Park, Sang-Kyu ;
Journal of electromagnetic engineering and science, volume 12, issue 3, 2012, Pages 223~225
DOI : 10.5515/JKIEES.2012.12.3.223
In this paper, we develop a symbol/frame time and carrier frequency synchronization scheme for multi-carrier signaling in wireless mobile channels. The proposed scheme achieves simultaneous time synchronization and carrier frequency offset estimation. Simulation results show that the frequency offset of multiple sub-carrier spacings can be estimated and that performance is improved with robustness regardless of the cyclic prefix length.