• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.54.4-54
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• 2002

1.Introduction 2. Channel Equalizer Using Adaptive Neural Network 3. Data Modulation and Demodulation Using Haar Transform 4. Binary Signal Transmission Using Haar Transform 5. Conclusion

• Journal of Communications and Networks
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• v.18 no.4
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• pp.589-599
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• 2016

Most existing resource management problem models arise from the original desire of allocating resources in either a user-centric or network-centric manner. The difference between their objectives is obvious: user-centric methods attempt to optimize the utility of individual users, whereas network-centric models intend to optimize the collective utilities of the entire network. In this paper, from the above two aspects, we analyze the robust power control problem in device-to-device (D2D) communication underlaying cellular networks, where two types of channel uncertainty set (e.g., ellipsoidal and column-wise) are considered. In the user-centric method, we formulate the problem into the form of a Stackelberg game, where the energy efficiency (EE) of each user is the ingredient of utility function. In order to protect the cellular user equipment's (CUE) uplink transmission, we introduce a price based cost function into the objectives of D2D user equipment (DUE). The existence and uniqueness of the game with the influence of channel uncertainty and price are discussed. In the network-centric method, we aim to maximize the collective EE of CUEs and DUEs. We show that by the appropriate mathematical transformation, the network-centric D2D power control problem has the identical local solution to that of a special case of the user-centric problem, where price plays a key role. Numerical results show the performance of the robust power control algorithms in the user-centric and network-centric models.

• Journal of Broadcast Engineering
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• v.13 no.1
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• pp.34-42
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• 2008

This paper proposes the mechanism which improves the qualify of video on a limited network bandwidth by applying the ROI technique to an H.264 Scalable Extension technique. The network environment assumed in this parer is the next generation network convergence environment in which the mobile device has one or more network interfaces. Therefore, we allocate the priority to video packets as the hierarchy structure of H.264 SVC-encoded video stream and ROI information, and transmit those packets over appropriate network channel for using those multiple network interfaces. This paper shows two experiments first one is extracting and allocating the video stream on an appropriate network channel, second one is unequal packet transmission by allocated priorities (e.g. ROI). Performance evaluations show that this approach delivers an improved decoded video quality when compared with conventional transmission schemes, especially on device which has multiple network interfaces.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.28B no.5
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• pp.369-381
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• 1991

In this paper, design algorithms for SMP(Single Mated Pair) and MMP (Multipli Mated Pair) structure of CCS (Common Channel Signaling) network are proposed through the study of the structure of CCS network. High reliability and fast messagy transfer time are the most important requirements for the CCS network. Based on it, three parameters such as monotraffic, reliability (maximum isolated SP(Signalling Point) number when any two STP(Signalling Transfer Points) fail and total network cost are defined. And the proposed algorithms different from preexisted algorithm that minimizes total network cost, maximize monotraffic with two constraints, reliability and total network cost. Comparing the experimental results of the proposed algorithms with those of the preexisted algorithm that minimizes total network cost, shows that the proposed algorithms produce a more reliable topology that has more monotraffic and a little higher total network cost. Additionaly, with the results of the proposed algorithms, SMP and MMP structures are compared.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.252-256
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• 2011

We analyze the channel capacity with considering the effect of the loading conditions of indoor PLC networks on channel state information. We consider various numbers of load for two kinds of the networks with regular length branches and a deployed network of indoor PLC. For calculating the channel capacity degradation, two noise scenarios and impedances are considered. From the simulation results, we suggest the robust regression lines for modeling the channel capacity degradation. In the cases of 0 $\Omega$ and $Z_0$ loads, natural log and linear function curve show the best goodness of fit, respectively. For the deployed indoor PLC network with 0 $\Omega$ loads, compared with the networks with regular length branches, the goodness of fit decreases by the amount of 0.12 and 0.15 for low noise and high noise scenarios, respectively. Using the regression lines, we can estimate the channel capacity degradation without measurement.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.39-52
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• 2006

As accelerates the technical evolution of high-speed network and progresses the digitalization of broadcasting network, TV channel service through satellite/cable/terrestrial networks becomes more stable and mature. However, TV channel service using IP network such as IPTV is recently emerging. Especially, when it comes to current mosaic EPG(Electronic Program Guide) as a channel guide, the implementation of EPG via IP network is under developing. Furthermore, the personal target mosaic EPG is not provided at all in the IPTV. This paper proposes a construction method of mosaic system which can support fixed and personalized mosaic EPG using IP network for viewers. The fixed mosaic EPG is made several steps as follows ; First, H/E generates several mosaic A/V streams. Then, which are transmitted to the STB in terms of multicasting via IP network. Finally, mosaic EPG is displayed on TV through STB. In addition, this paper describes a construction model of the personalized A/V mosaic EPG that represents each person's favorite channels according to their tastes and interests. As for the contributions. The TV channel guide using IP network enable viewer to select channel more easily with practical adaptation of multi-channel expansibility and sufficient usability. In addition, through personal mosaic EPG, a number of viewers can compose their own mosaic EPG and enjoy a variety of channel easily in accordance with their preferences. Finally, the personal mosaic EPG can prohibit non-adult users from connecting adult-only contents more efficiently.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.7-13
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• 2009

In This Paper, we propose relay schemes for network-coding based two-way relay communication in multi relay channel. Two-way relay channel communication is a bi-directional communication that two users exchange their data with the help of a relay. Network-coding based Two-way relay communication can achieve more throughput compared to conventional two-way relay communication. In this paper, we propose relay selection schemes to provide maximum performance considering instantaneous signal-to-noise in multi-relay channel. Simulation results show that the proposed relay selection schemes can provide diversity order according to the number of relays.

• Journal of KIISE:Information Networking
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• v.37 no.4
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• pp.312-316
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• 2010

In this paper, we propose a game theoretic channel sharing model that allocates resources of a base station between MNO(Mobile Network Operator) and MVNO(Mobile Virtual Network Operator) in a fair and efficient manner. Considering the input traffic loads of MNO and MVNO, the proposed model uses the bargaining game theory to allocate channel resources between MNO and MNVO. When the input loads of the carriers are asymmetric, the proposed model increases the resource utilization by allocating more channel resources to the operator with high input load. In addition, the proposed model prevents the quality of service of an operator from degrading even if the input load of the other operators increases excessively.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06d
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• pp.187-189
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• 2012

The medium access control (MAC) protocol is designed only for single channel in the IEEE 802.11 standard. That means the throughput of the network is limited by the bandwidth of the single channel. The multiple channels can be exploited to get more concurrent transmission. In this paper, we propose a novel Multi-channel MAC that utilizes the channel more efficiently than other Multi-channel MAC protocols.

• Journal of Communications and Networks
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• v.8 no.1
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• pp.13-20
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• 2006

In cellular mobile communications, how to achieve optimum system capacity with limited frequency spectrum is one of the main research issues. Many dynamic channel assignment (DCA) schemes have been proposed and studied to allocate the channels more efficiently, thus, the capacity of cellular systems is improved. Reuse partitioning (RP) is another technique to achieve higher capacity by reducing the overall reuse distance. In this paper, we present a network-based DCA scheme with the implementation of RP technique, namely dynamic reuse partitioning with interference information (DRP-WI). The scheme aims to minimize the effect of assigned channels on the availability of channels for use in the interfering cells and to reduce their overall reuse distances. The performance of DRP-WI is measured in terms of blocking probability and system capacity. Simulation results have confirmed the effectiveness of DRP-WI scheme. Under both uniform and non-uniform traffic distributions, DRP-WI exhibits outstanding performance in improving the system capacity. It can provide about 100% capacity improvement as compared to conventional fixed channel assignment scheme with 70 system channels.