• Journal of Communications and Networks
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• v.12 no.5
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• pp.411-432
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• 2010

We consider three different secure broadcasting scenarios: i) Broadcast channels with common and confidential messages (BCC), ii) multi-receiver wiretap channels with public and confidential messages, and iii) compound wiretap channels. The BCC is a broadcast channel with two users, where in addition to the common message sent to both users, a private message, which needs to be kept hidden as much as possible from the other user, is sent to each user. In this model, each user treats the other user as an eavesdropper. The multi-receiver wiretap channel is a broadcast channel with two legitimate users and an external eavesdropper, where the transmitter sends a pair of public and confidential messages to each legitimate user. Although there is no secrecy concern about the public messages, the confidential messages need to be kept perfectly secret from the eavesdropper. The compound wiretap channel is a compound broadcast channel with a group of legitimate users and a group of eavesdroppers. In this model, the transmitter sends a common confidential message to the legitimate users, and this confidential message needs to be kept perfectly secret from all eavesdroppers. In this paper, we provide a survey of the existing information-theoretic results for these three forms of secure broadcasting problems, with a closer look at the Gaussian multiple-input multiple-output (MIMO) channel models. We also present the existing results for the more general discrete memoryless channel models, as they are often the first step in obtaining the capacity results for the corresponding Gaussian MIMO channel models.

• Journal of Communications and Networks
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• v.18 no.2
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• pp.173-181
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• 2016

In this paper, we address a new robust optimization problem in a multiuser multiple-input single-output broadcasting system with simultaneous wireless information and power transmission, where a multi-antenna base station (BS) sends energy and information simultaneously to multiple users equipped with a single antenna. Assuming that perfect channel-state information (CSI) for all channels is not available at the BS, the uncertainty of the CSI is modeled by an Euclidean ball-shaped uncertainty set. To optimally design transmit beamforming weights and receive power splitting, an average total transmit power minimization problem is investigated subject to the individual harvested power constraint and the received signal-to-interference-plus-noise ratio constraint at each user. Due to the channel uncertainty, the original problem becomes a homogeneous quadratically constrained quadratic problem, which is NP-hard. The original design problem is reformulated to a relaxed semidefinite program, and then two different approaches based on convex programming are proposed, which can be solved efficiently by the interior point algorithm. Numerical results are provided to validate the robustness of the proposed algorithms.

• Korean journal of communication and information
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• v.66
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• pp.110-132
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• 2014

This study attempts to redefine the concept of 'fairness' of Korean public broadcasting and tries to build a new model for evaluating the fairness of Korean public broadcasting. The author insists that the fairness in public broadcasting consists of binary components of the public and rightful reporting, and views that the public reporting represents of neutralness, balance and impartiality while the rightful reporting represents of factuality, multiplicity and the protection of social minorities. The author suggests that two criteria of the public and rightful reporting results in four models of 'shepherd', 'acrobat', 'tribune', and 'trumpeter' in accord with its focus on the public and the rightful reporting. Survey toward the professionals in public broadcasting in academia was conducted and addressed the fact that Korean public broadcasting is close to the trumpeter model with some feature of acrobat.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1940-1943
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• 2002

In this paper, we presented the design and implementation of 155Mbps satellite Modem adaptively compensated against the rain attenuation. In order to compensate the rain attenuation over high-speed satellite ink, the adaptive coding schemes with variable coding rates and the pragmatic TCM that can be decoded both the QPSK and TC-8PSK using same Viterbi decoder was studied and analyzed. The pragmatic TCM with rate 213, selected to the optimal parameters for implementation, was modeled by VHDL in this paper. The key design issues are how to achieve a high data rate and how to integrated into a single ASIC chip various functions such as the different data rates, Scrambler/descrambler, Interleaver, Encoder/decoder, and BPSK/QPSK/8PSK modulator/demodulator. The implemented 155M0ps adaptive MODEM has the simplified interface circuits among the many functional blocks, and parallel processing architecture to achieve the high data rate. This 155Mbps adaptive MODEM was designed and implemented by single ASIC chip with the 0.25 $\mu\textrm{m}$ CMOS standard cell technology.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.10
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• pp.1990-1998
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• 2017

The success of naval operation prioritizes the implementation of a robust communication network that delivers accurate and prompt communications to one another. The satellite, which is the main communication network of the military, is required to construct a preliminary communication network because of the enemy radio disturbance and weak point of fixed antenna. The military operational communication network has been in transition from voice-centered wireless communication network to text message-based communication network. In this paper we suggest an enhanced communication method built on Roll Call, the main communication method of ROK Navy operating tactical data link called Link-11. Simulation results display that the proposed method reduces the transmission time per unit frame by 4.3 times compared to the Roll Call and 6.3 times compared with the Round Robin & Broadcasting; it is also proved that the higher the direct reception rate, the shorter the transmission time required by 1.6 times maximum.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.394-400
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• 2016

This study reviewed critically the music regulations of broadcasting advertising and analyzed the post reviews of Korea Communications Standards Commission(KCSC) to find their problems and suggest alternatives for their improvements. As general core regulations, lyrics changes of children's song is banned except in non-commercial public advertising and lyrics changes to folk songs are permitted unless it includes the product related expressions, such as brand name; both of their arrangements are permitted. According to the items, the lyrics of the CM song of drug advertising should not include its brand name; alcoholic beverage advertising is banned if the lyrics of the CM song include product-related brand name or an expression encouraging drinking. The rationales of these regulations of restrictions or prohibitions of music in broadcasting advertising are unclear and are insufficient. Therefore, it will be necessary to improve them based on the evidence or knowledge by more valid research in the future.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.273-278
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• 2012

Wired communication signals that are generated in a wheelchair and using GPS to gather speed in this study. And occupants in the helmet, and save your current location information in a wheelchair and speed information that is passed by smartphone to take advantage of the Black Box App and radio feature multi-Communications App S/W development.The results of this study can be utilized effectively a pseudo-real-time information can be shared in each other's wheelchair with many people moving. Limitations of the study at the Institute of Experimental concrete measures for the commercial approach to the development of operational models as required.

• Proceedings of the Safety Management and Science Conference
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• 2008.11a
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• pp.201-214
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• 2008

IPTV services, as the convergence service of communication and broadcasting, are regarded as the essential information communication media in the New Economy era by providing the consumers with various services through the collaboration among communications, broadcasting and many of other media service providers. The research starts with recognition that, in the new media era, where communication and broadcasting are converging, there are endless demands for new services and various contents, which are driving forces behind the business model of IPTV. In other words, the research expected that customer satisfaction and purchase intention would be different according to the service quality(contents). It was expected that the difference of the perceived service quality(contents) could cause the difference of the process of adopting new technologies. The study on how consumers are satisfied with services provided, and which factors of the service quality have a more significant effect on consumer satisfaction will provide very valuable information for forecasting future trends in the IPTV market. The research tried to investigate factors which influence on consumer satisfaction and loyalty through an empirical survey with real users of IPTV services. Based on the results, the research suggested effective ways of diffusing IPTV.

• Journal of Astronomy and Space Sciences
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• v.20 no.4
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• pp.339-350
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• 2003

Engineering qualification model payload for a communications and broadcasting satellite(CBS) was developed by ETRI from May, 2000 to April, 2003. For. the purpose of functional test and verification of the payload, a real-time hardware-in-the-loop(HITL) CBS simulator(CBSSIM) was also developed. We assumed that the spacecraft platform for the CBSSIM is a geostationary communication satellite using momentum bias three-axis stabilization control technique based on Koreasat. The payload hardware is combined with CBSSIM via Power, Command and Telemetry System(PCTS) of Electrical Ground Support Equipment(EGSE). CBSSIM is connected with PCTS by TCP/IP and the payload is combined with PCTS by MIL-STD-1553B protocol and DC harness. This simulator runs under the PC-based simulation environment with Windows 2000 operating system. The satellite commands from the operators are transferred to the payload or bus subsystem models through the real-time process block in the simulator. Design requirements of the CBSSIM are to operate in real-time and generate telemetry. CBSSIM provides various graphic monitoring interfaces and control functions and supports both pre-launch and after-launch of a communication satellite system. In this paper, the HITL simulator system including CBSSIM, communications payload and PCTS as the medium of interface between CBSSIM and communications payload will be described in aspects of the system architecture, spacecraft models, and simulator operation environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3A
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• pp.345-355
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• 2006

The RF Module which can be adjusted for a digital terrestrial and multi standard(DVB-C, ISDB-T, DVB-H) reception is developed. The Module by single conversion does divide a broadband($45MHz{\sim}860MHz$) broadcasting channels into three-bands(UHF, VHF_HIGH, VHF_LOW) to satisfy some electrical performances such as image signal rejection, phase noise, IF flatness etc and digital reception specifications such as analog and digital adjacent channel protection, co-channel protection which is important in environment with co-existence both analog and digital broadcasting systems.