Byung-Jang Jeong
Electronics and Telecommunications Research Institute
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Publication
Featured researches published by Byung-Jang Jeong.
international conference on information and communication technology convergence | 2011
Hyunduk Kang; Donghun Lee; Byung-Jang Jeong; Allen C. Kim
Using OPNET simulation we evaluate performance of 802.22 system operating over TV white space when 802.11af system coexist with 802.22 system at a given geo-location considering co-channel interference. To do that, we consider coexistence scenario that 802.11af system is located near 802.22 base station (BS) or customer-premises equipment (CPE). We compare upstream and downstream performance of 802.22 system. Upstream performance of 802.22 system is heavily degraded when 802.11af system exists near 802.22 CPE due to significant loss of upstream MAP data at 802.22 CPE.
2011 IEEE MTT-S International Microwave Workshop Series on Intelligent Radio for Future Personal Terminals | 2011
Jinhyung Oh; Sang-Won Kim; Byung-Jang Jeong
Cognitive Radio (CR) technology is one of the favorable technology to efficiently deploy the underutilized frequency spectrum. Currently, the Federal Communications Commission (FCC) allowed TV white space (TVWS) which should protect the licensed user communication to utilize for data communication. The first actual deployment of communication system operating on TVWS is implemented in our group. However, it operates in SISO and single-channel procedure. So, we will develop a second version test-bed operating various modes such as SIMO, 2×2 MIMO and multi-channel communications. From these diverse operation methods, we expect that data rate is enhanced. In this paper, we will introduce a CR RF transceiver which is equipped in our second version of test-bed based on ECMA-392 international standard.
international conference on communications | 2009
Dongming Wang; Wenjin Wang; Xiangyang Wang; Byung-Jang Jeong; Soo Chang Kim; Jae Young Ahn
In this paper, we present the link level performance of SC-FDMA with SDMA (Space Division Multiple Access), real channel estimation and low complexity frequency-domain turbo equalization. We give the implementation of the minimum-mean-squared-error based turbo equalization which is suitable for DFT-S-OFDM based SDMA systems. The block error rate performance of SC-FDMA and OFDMA with SDMA and turbo receiver is compared under different code rate and modulation order.
international conference on consumer electronics | 2011
Jung-Sun Um; Sung-Hyun Hwang; Byung-Jang Jeong; Chang-Joo Kim
The interest on Cognitive Radio (CR) technology is increased to efficiently utilize the unused spectrum. To investigate the feasibility of the CR system operating in TV white space, we have developed a CR test-bed which is based on the Ecma-392 standard. This paper presents the modem algorithms and implementation of physical layer module within the CR test-bed.
The Journal of Korean Institute of Communications and Information Sciences | 2011
Sunmin Lim; Hoiyoon Jung; Byung-Jang Jeong
For efficient utilization of spectrum resources in TV white space after DTV transition, FCC allowed usage of the spectrum for CR system. The CR system is required to cognize channel usage state for utilizing the unused spectrum in TV white space which coexists various primary and secondary systems. In the meantime, as a demand for high throughput communication had been increased recently, CR systems also consider to adopt channel bonding technology, thus spectrum sensing for channel bonded system is essentially required. In this paper, we propose a novel spectrum sensing algorithm for channel bonding system using a single channel receiver. For IEEE 802.l1af signal, the proposed algorithm provide detection probability of 90% with false alarm probability 10% at SNR -18dB for single channel system and at SNR -7dB for 8 channel bonded system, respectively. Utilizing the proposed scheme, we can detect channel bonded signal using only a single receiver, therefore system overhead for spectrum sensing can be reduced significantly.
The Journal of Korean Institute of Communications and Information Sciences | 2011
Sunmin Lim; Hoiyoon Jung; Sang-Won Kim; Byung-Jang Jeong
FCC of U.S. permitted usage of unlicensed system on unused spectrum in TV white space after DTV transition. The unlicensed systems are required to avoid harmful interference to licensed users by employing geo-location database and spectrum sensing. The conventional spectrum sensing algorithms for ATSC signal were focused on detection of pilot signal. However, they can not guarantee detection of ATSC signal when pilot signal is attenuated by channel environment such as fading. To overcome drawbacks of conventional schemes, in this paper, we propose a signal detection and data fusion algorithm using cyclo-stationary feature weighted by signal energy. Simulation results verify that the proposed algorithm can provide 2dB SNR gain for 90% detection probability compare with the conventional scheme. We can reduce quiet period for spectrum sensing and improve signal detection probability by employing the proposed algorithm.
The Journal of Korean Institute of Communications and Information Sciences | 2011
Sunmin Lim; Hoiyoon Jung; Sang-Won Kim; Byung-Jang Jeong
After permission for utilization of TV white space by FCC, a lot of attentions are focused on spectrum sensing, and various spectrum sensing methods have been proposed. However, they do not consider real environment, thus they are hard to achieve the required performance. In this paper, we propose resolutions for the problem which could be occurred in implementation of spectrum sensing module and verify performance of the proposed methods with computer simulation. The first proposed method utilizes channel status information to separate received signal and spurious for reducing false alarm probability caused by system internal spurious. The another proposed scheme is subband normalization method to prevent miss detection caused by multiple narrow band signals with different received signal strength. The simulation results verify that we can prevent false alarm cause by spurious components with the proposed system internal spurious cognition. Moreover, the proposed subband normalization method shows that it could overcome performance degradation caused by received signal strength difference.
Archive | 2007
Hyo-jin Lee; Hyun-Kyu Chung; Jae Kyun Kwon; Jae-Young Ahn; Heesoo Lee; Byung-Jang Jeong
Archive | 2007
In-Sook Park; Byung-Jang Jeong; Hyun-Kyu Chung
Archive | 2007
Taegyun Noh; Minjoong Rim; Byung-Jang Jeong; Hyo-jin Lee; Hyun-Kyu Chung