• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12C
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• pp.997-1005
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• 2008

In this paper, we proposed advanced T-DMB system which is based on Eureka-147 using UEP coding methods and hiererchical modulation for providing additional services while maintaining BER performance. We simulated the proposed advanced T-DMB system using unequal l6QAM modulation scheme combined with various bit split methods and coding methods such as double binary turbo code of DVB-RCS standard and LDPC code of DVB-S2 standard. In the simulation results, double binary turbo code and LDPC code of proposed advanced T-DMB system have coding gain of 2dB and 3.5dB compared to conventional T-DMB system respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.1892-1897
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• 2012

In this paper, efficient CNU(Check Node Update) algorithms are analyzed for high speed LDPC decoding in DVB-S2 standard. In aspect to CNU methods, there are some kinds of CNU methods. Among of them, MP (Min Product) method is quite often used in LDPC decoding. However MP needs LUT (Look Up Table) that is critical path in LDPC decoding speed. A new SC-NMS (Self-Corrected Normalized Min-Sum) method is proposed in the paper. NMS needs only normalized scaling factor instead of LUT and compensates the overestimation of MP approximation. In addition, SC method is proposed. It gives a faster convergence toward a decoded codeword. If a message change its sign between two iterations, it is not reliable and to avoid to propagate noisy information, its module is set to 0. The performance of SC-NMS has a little degrade compare to MP by 0.1 dB, however considering computational complexity and decoding speed, SC-NMS algorithm is optimal method for CNU algorithm.

• Convergence Security Journal
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• v.22 no.2
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• pp.91-98
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• 2022

Because the movie has the characteristics of a cultural product where experience is important, a promotional strategy is used to convert viewers into movie audiences by providing indirect experiences of movies through professional movie information programs. Considering that the movie information program is a strategic publicity medium that raises the audience's intention to watch a movie, a study on the data service that provides useful additional information to the viewer in conjunction with the movie information program is meaningful. Against this background, this study contains the core research contents in the development of data service linked with movie information program. Specifically, additional information of the movie information program was defined. And to provide the additional information to the data service, the digital broadcasting international standard DVB-SI-based additional information transmission method was devised.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.1
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• pp.205-212
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• 2010

This paper describes a core generator (FCore_Gen) which generates Verilog-HDL models of 640 different FFT/IFFT cores with selected parameter value for OFDM-based communication systems. The generated FFT/IFFT cores are based on in-place single memory architecture and use a hybrid structure of radix-4 and radix-2 DIF algorithm to accommodate various FFT lengths. To achieve both memory reduction and the improved SQNR, a conditional scaling technique is adopted, which conditionally scales the intermediate results of each computational stage. The cores synthesized with a $0.35-{\mu}m$ CMOS standard cell library can operate with 75-MHz@3.3-V, and a 8,192-point FFT can be computed m $762.7-{\mu}s$, thus the cores satisfy the specifications of wireless LAN, DMB, and DVB systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.10
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• pp.2207-2214
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• 2010

Underwater acoustic(UWA) communication has multipath error because of reflection by sea-level and sea-bottom. The multipath of UWA channel causes signal distortion and error floor. In this paper, we proposed split input bits of channel decoder using method of maximum value, average value, LLR value for optimal estimation. Channel coding method is LDPC(N size=16000) standard in DVB-S2. As shown in simulation results, the performance of LLR value method is better than other methods.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.253-256
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• 2009

This paper describes a core generator (FFT_Core_Gen) which generates Verilog HDL models of 8 different FFT/IFFT cores with $N=64{\times}2^k$($0{\leq}k{\leq}7$ for OFDM-based communication systems. The generated FFT/IFFT cores are based on in-place single memory architecture, and use a hybrid structure of radix-4 and radix-2 DIF algorithm to accommodate various FFT lengths. To achieve both memory reduction and the improved SQNR, a conditional scaling technique is adopted, which conditionally scales the intermediate results of each computational stage, and the internal data and twiddle factor has 14 bits. The generated FFT/IFFT cores have the SQNR of 58-dB for N=8,192 and 63-dB for N=64. The cores synthesized with a $0.35-{\mu}m$ CMOS standard cell library can operate with 75-MHz@3.3-V, and a 8,192-point FFT can be computed in $762.7-{\mu}s$, thus the cores satisfy the specifications of wireless LAN, DMB, and DVB systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.9
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• pp.2029-2035
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• 2013

In this paper, we presented non-uniform quantization method for LDPC decoder specified in DVB-S2 standard. There are some problems in order to implement LDPC decoder in aspect to algorithm and implementation. In algorithm aspect, because of large number of iterations, LDPC decoding in general give rise to a large number of computation operations, mass power consumption, and decoding delay. Therefore, this paper studies Horizontal Shuffle Scheduling (HSS) algorithm which reduced iteration number without performance loss. In aspect of implementation, there are some solutions to improve the decoding speed, however this paper focused on non-uniform quantization which reduce the quantization bits of LDPC decoder. In simulation results, Decoding throughput of HSS LDPC decoder based on non-uniform quantization is 816Mbps and it improved 12% compared to conventional one.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12C
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• pp.983-990
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• 2008

In communication systems, initial acquisition is required for the reliable transmission performance, and the analysis of the acquisition performance over various communication environments including different signal-to-noise ratios plays an important role in communication system design. Usage of differential correlation methods in initial synchronization procedure is desired when frequency offsets exist, and additional performance improvement can be achieved through proper modifications of conventional correlation schemes. In this paper, we derive the error probability of the initial acquisition and express it in terms of the Marcum Q-function, via statistical modeling of the differential correlator output. The result is generalized to the error probabilities of the extended differential correlation methods using the complex- and magnitude-sum of the correlator outputs. The derived probabilities can be applied for the acquisition performance verification of various communication systems including the DVB-S2 standard.

• Convergence Security Journal
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• v.17 no.2
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• pp.119-126
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• 2017

Although the data service of the digital broadcasting has been regarded as the representative service of the broadcasting and communication convergence, it, however, has failed to gain the popularity with the viewers due to the viewer's viewing modality of focusing only on the TV programs. Based on the experts' opinions that the data service should step up so that using a data service while watching a TV program creates a synergy effect, the paper proposes a method for allowing a data service to utilize the information of a TV program. The method has a tool for describing the information of a TV program's content, which changes as time goes on and provides a mechanism for transmitting the information in the way compatible to the digital broadcasting standard. As an application of the method, with a domestic data service developing company, we have developed a ticker data service that shows the information (e.g., actors, places, sponsors, etc.) of a drama.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.444-450
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• 2011

A novel method that utilizes poly(5-methyl-2-thiozyl methacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid-co-divinylbenzene) [MTMAAm/AMPS/DVB] as a solid-phase extractant was developed for simultaneous preconcentration of trace Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), and Zn(II) prior to the measurement by flame atomic absorpiton spectrometry (FAAS). Experimental conditions for effective adsorption of the metal ions were optimized using column procedures. The optimum pH value for the simultaneously separation of the metal ions on the new adsorbent was 2.5. Effects of concentration and volume of elution solution, sample flow rate, sample volume and interfering ions on the recovery of the analytes were investigated. A high preconcentration factor, 100, and low relative standard deviation values, $\leq$1.5% (n = 10), were obtained. The detection limits (${\mu}gL^{-1}$) based on the 3s criterion were 0.18 for Cd(II), 0.11 for Co(II), 0.07 for Cr(III), 0.12 for Cu(II), 0.18 for Fe(III), 0.67 for Mn(II), 0.13 for Ni(II), 0.06 for Pb(II), and 0.09 for Zn(II). The validation of the procedure was performed by the analysis of two certified reference materials. The presented method was applied to the determination of the analytes in various environmental samples with satisfactory results.