• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.3
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• pp.177-185
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• 2017

In this paper, we proposed a concept of interference load to analyze the performance of spectrum sharing technologies in unlicensed frequency bands. The interference load can quantitatively compare the technical properties of various spectrum sharing technologies, such as frequency hopping(FH), duty cycle(DC), listen-before-talk(LBT). Therefore, it can help to evaluate whether a local regulation about spectrum sharing is reasonably established or not. In order to verify the suggested concept, we applied it to 2.4 GHz frequency bands. Also, we demonstrated a real-time test-bed. Two bit error rate(BER) curves for FH with 10 random channels and DC of 10 %, show such good agreement that our proposed concept is expected to be widely used to assess various spectrum sharing technologies.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.1
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• pp.68-75
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• 2011

The performance of peripheral devices is improving rapidly to meet the needs of users for multimedia data. Therefore, the peripheral interface with wide bandwidth and high transmission rate becomes necessary to handle large amounts of data in real time for multiple high-performance devices. PCI Express is a fast serial interface with the use of packets that are compatible with previous PCI and PCI-X. In this paper, we design and verify general peripheral interface using serial link. It includes two kinds of traffic class (TC) labels which are mapped to virtual channels (VC). The design adopts TC/VC mapping and the scheme of arbitration by priority. The design uses a packet which can be transmitted through up to four transmission lanes. The design of general peripheral interface is described in Verilog HDL and verified using ModelSim. For FPGA verification, Xilinx ISE and SPARTAN XC3S400 are used.We used Synopsys Design Compiler as a synthesis tool and the used library was MagnaChip 0.35um technology.

• Journal of Internet Computing and Services
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• v.10 no.1
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• pp.123-134
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• 2009

The CRM(Customer Relationship Management) is a business strategy model which can reap higher profits and can provide a competitive edge to an enterprise in today's new business environments. Early next year (2009), the Capital Market Consolidation Act will be in effect in South Korea. This is required for a qualitative growth to provide QoS (Quality of Service) and ensure growth in finance, IT industry & service. Accordingly, the securities and insurance companies, banks and other financial institutions make efforts to improve their derivative financial product and also enhance their services. In this paper we design and implement a Channel Server model for a Scalable Service Channel Server to efficiently manage the high volumes of inbound customer interactions based on the requirements of a CRM center. The proposed Scalable Service Channel Server supports integration with other third party service and standardization of multiple inbound service channels. The proposed model can be efficiently used in an inbound CRM center of any banking, finance, securities and insurance establishments.

• The Journal of the Korea Contents Association
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• v.13 no.6
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• pp.20-29
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• 2013

The compression of video data is intended for real-time transmission of band-limited channels. Compressed video bit-streams are very sensitive to transmission error. If we lose packets or receive them with errors during transmission, not only the current frame will be corrupted, but also the error will propagate to succeeding frames due to the spatio-temporal predictive coding structure of sequences. Error detection and concealment is a good approach to reduce the bad influence on the reconstructed visual quality. To increase concealment efficiency, we need to get some more accurate error detection algorithm. In this paper, We hide specific data into the motion vector difference of each macro-block, which is obtained from the procedure of inter prediction mode in H.264/AVC. Then, the location of errors can be detected easily by checking transmitted specific data in decoder. We verified that the proposed algorithm generates good performances in PSNR and subjective visual quality through the computer simulation by H.324M mobile simulation tool.

• Journal of Broadcast Engineering
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• v.14 no.2
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• pp.178-188
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• 2009

In this paper, we propose the method which provides efficient sub-channel allocation for handoff and new call supporting multi-media service in AMC-based OFDMA system. Firstly, we apply the multi-band method which provides different AMC method according to the location of user terminals. Also, in OFDMA system environment that a base station has a lot of sub-channels, we adopt the sub-channel allocation scheme that provides a higher priority to handoff call and real-time service about handoff and new calls with multi-meida service. The simulation results show that the proposed scheme plays a role in increasing the number of new and handoff calls meeting the required blocking rate.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12A
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• pp.1182-1188
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• 2006

Adaptive OFDM(Orthogonal Frequency Division Multiplexing) improves data capacity and system performance over multipath fading by adaptively changing modulation schemes according to channel state information(CSI). To achieve a good performance in adaptive OFDM systems, CSI should be transmitted from receiver to transmitter in real time through feedback channel. However, practically, the CSI feedback delay d which is the sum of the data processing delay and the propagation delay is not negligible and damages to the reliability of CSI such that the performance of adaptive OFDM is degraded. This paper presents an adaptive OFDM system with a multistep predictor on the frequency axis to effectively compensate the multiple feedback delays $d(\geq2)$. Via computer simulation we compare the proposed scheme and existing adaptive OFDM schemes with respect to data capacity and system performance.

• Journal of Internet Computing and Services
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• v.21 no.2
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• pp.65-72
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• 2020

In this paper, a USB module with fingerprint recognition was designed as a distributed node of blockchain on distributed ID (DID, distributed ID) for user identification. This biometric-linked fingerprint recognition device was verified for the real-time authentication process of authentication transaction with FIDO(Fast IDentity Online) server. Blockchain DID-based services were proposed like as a method of individual TV rating survey, and recommending service for customized shopping channels, and crypto-currency, too. This DID based remote service can be improved by recognizing of channel-changing information through personal identification. The proposed information of production purchase can be shared by blockchain. And customized service can be provided for the utilization of purchase history in shoppingmall using distributed ID. As a result, this blockchain node-device and Samsung S10 Key-srore with FIDO service can be certified for additional transactions through various biometric authentication like fingerprint, and face recognition.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.2
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• pp.86-94
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• 2007

The NoC (network-on-chip) approach is a promising solution to the increasing complexity of on-chip communication problems because of its high scalability. But, NoC applications generally consume a lot of power, because they require a large design space to accommodate many parallel IPs and network communication channels. It is not easy to analyze the power consumption of NoC applications with conventional simulation methods using simple power models. In addition, there are also many limitations in using sophisticated simulation models because they require long execution time and large efforts. In this paper, we apply a cycle-accurate energy measurement technique and tool to the FPGA prototypes, which are generally used to verify the correctness of SoC designs, as a practical indication of the power consumption of real NoC applications. An NoC-based JPEG encoder implementation is used as a case study to demonstrate the effectiveness of our approach.

• Journal of Advanced Navigation Technology
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• v.22 no.3
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• pp.213-219
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• 2018

In this paper, we propose a design method and process for hardware and software of hybrid V2X communication module that supports both C-ITS communication protocol designed for vehicle environment and Legacy LTE communication technology. C-ITS is suitable for safety service applications due to its low latency characteristics, and Legacy LTE is a technology suitable for non-safety applications such as traffic information and infotainment due to high latency and high capacity. The hybrid V2X communication module supports multiple communication technologies of WAVE and LTE, in which WAVE supports multiple channels, so that it is designed to transmit road information such as LDM and positioning correction information to an autonomous vehicle in real time. The main design results presented in this paper will be applied to the implementation of future hybrid V2X communication terminals for vehicles.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1831-1838
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• 2015

In this paper, a method of implementing a communication network in ship, which exploits a powerline-based legacy-line communication system (LLC), is presented. We develop an inductive coupling unit and a multi-interface device to connect a data communication terminal to the powerline. As a result of operation tests for the ship under working, the implemented LLC shows a transmission rate of at least 25.8 Mbps in the distance of 200 m away with 100% success rate. Thus, the system can be a useful alternative to implement a communication network in ship without additional channels. Being easy to be implemented and supporting various interfaces for data communication, the presented system will be very effective when a real-time monitoring system is launched in future digital ship.