• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
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• pp.378-381
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• 2003

The Channel Coding Unit (CCU) is an integral component of Payload Data Transmission System (PDTS) for the Multi-Spectral Camera (MSC) data. The main function of the CCU is channel coding and encryption. CCU has two channels (I ＆ Q) for data processing. The input of CCU is the output of DCSU (Data Compression ＆ Storage Unit). The output of CCU is the input of QTX which modulate data for RF communication. In this paper, there are the overview, short H/W description and operation concept of CCU.

• International Journal of Internet, Broadcasting and Communication
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• 제13권4호
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• pp.39-47
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• 2021

Lempel-Ziv coding is one of the most famous source coding schemes. The output of this source coding is usually a non-uniform code, which requires additional source coding, such as arithmetic coding, to reduce a redundancy. However, this additional source code increases complexity and decoding latency. Thus, this paper proposes the optimal maximum a-posteriori (MAP) receiver for non-uniform source non-orthogonal multiple access (NOMA) with symmetric superposition coding (SSC). First, we derive an analytical expression of the bit-error rate (BER) for non-uniform source NOMA with SSC. Then, Monte Carlo simulations demonstrate that the BER of the optimal MAP receiver for the non-uniform source improves slightly, compared to that of the conventional receiver for the uniform source. Moreover, we also show that the BER of an approximate analytical expression is in a good agreement with the BER of Monte Carlo simulation. As a result, the proposed optimal MAP receiver for non-uniform source could be a promising scheme for NOMA with SSC, to reduce complexity and decoding latency due to additional source coding.

• 한국통신학회논문지
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• 제29권6A호
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• pp.640-650
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• 2004

본 논문에서는 Multiple Put-Multiple output Orthogonal Frequency Division Multiplexing(MIMO-OFDM) 시스템을 위한 채널 추정 기법으로 space-time block c첨ing(STBC) 기법과 space-frequency block coding(SFBC) 기법을 제안한다. 제안된 방식은 각 송신 안테나에서 서로 직교성을 갖는 훈련 심볼을 전송함으로써 수신 안테나에서는 각 송수신 안테나 사인의 채널 계수를 추정한다. 제안된 알고리즘은 IEEE 802.11a 시스템 기반의 MIMO-OFDM 시스템에 적용해 성능 개선 효과를 확인해 보았다. 그 결과 제안된 방법이 기존의 방법보다 더 정확한 채별 계수 추정이 가능함을 확인할 수 있었다. 모의실험은 기존의 추정기법과 제안된 추정 기법이 적용된 시스템을 50ns 와 150ns 의 RMS 지연 확산을 갖는 다중 경로 페이딩 환경에서 수행되었으며 각 변복조 방식에 따른 비트 오류 성능 개선 정도를 확인해 보았다.

• 한국지능시스템학회논문지
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• 제16권5호
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• pp.562-567
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• 2006

모델 예측 제어 시스템은 이동 제어 구간에서 원하는 출력과 예측된 출력의 차이를 최소화하는 현재의 제어 입력을 적용하는 방식을 사용한다. 제약조건이 있는 경우이거나 비선형 시스템 문제의 경우는 주어진 함수를 최소화하는 최적화 문제를 풀기가 힘들다. 본 논문에서는 모델 예측 제어 시스템의 최적화 문제를 실수 코딩 유전 알고리즘을 이용하여 효율적으로 구할 수 있음을 보인다. 또한 실수코딩 유전알고리즘이 여러 가지 면에서 디지털코딩 유전알고리즘보다 더 자연스럽고 유리함을 모의실험을 통해 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권8호
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• pp.2875-2893
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• 2015

Existing coding aware routing algorithms focused on novel routing metric design that captures the characteristics of network coding. However, in packet coding algorithm, they use opportunistic coding scheme which didn't consider the queue state of the coding node and are equivalent to the conventional store-and-forward method in light traffic load condition because they never delay packets and there are no packets in the output queue of coding node, which results in no coding opportunity. In addition, most of the existing algorithms assume that all flows participating in the network have equal rate. This is unrealistic since multi-rate environments are often appeared. To overcome above problem and expand network coding to light traffic load scenarios, we present an enhanced coding-aware routing algorithm based on queue state and local topology (OQMCAR), which consider the queue state of coding node in packet coding algorithm where the control policy is of threshold-type. OQMCAR is a unified framework to merge single rate case and multiple rate case, including the light traffic load scenarios. Simulations results show that our scheme can achieve higher throughput and lower end-to-end delay than the current mechanisms using COPE-type opportunistic coding policy in different cases.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.477-480
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• 1988

A new image coding system called knowledge- based coding is presented which uses positively the knowledge for coding objects. The 3- dimensional model and the psychological knowledge for a person's face can be used as the knowledge for a coding system, when a person's face is coding object. A transmitter analyzes input images and a receiver synthesizes output images using them. The construction of 3-dimensional model and the introduction of the psychological knowledge to the new coding system are discussed. The basic facial expressions are synthesized from a neutral face using them. The synthesized images are very natural.

• 한국컴퓨터정보학회논문지
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• 제23권1호
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• pp.49-55
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• 2018

In this paper, we propose a design and development of instructional cards to understand the grammar of coding, solving the problems and extending the computational thinking in the robot-driven environment. First, we designed the input/output module of the robot to process the coding grammar through the function analysis of the robot. And we designed the module of command card to learn coding grammar using color sensors. We have proven the validity of the designed instruction card by examining the experts to see if it is suitable for coding grammar learning. Designed robot and command card were developed with 28 cards and sensor robot. After applying the developed robot and command card to the elementary school students, the questionnaire showed that students grow the understanding and confidence of coding. In addition, students showed an increased need for programming learning.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.451-456
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• 1989

New image coding system for facial images called 'Knowledge-based image coding' is described, in which input image is analyzed and output image is synthesized using analysis results. Analysis and synthesis method of facial expressions are presented. Synthesis rules are determined on the basis of facial muscles and are also used in analysis process to produce a faithful reconstruction of the original image. A number of examples are shown.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.29-32
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• 2002

본 논문은 수평적 시공간 부호화 기법(Horizontal Space-Time Coding)과 송수신단에 별도의 빔형성 기법을 결합한 JBSTC(Joint Beamforming Space-Time Coding) 구조에 대한 제안 및 동작원리를 기술하고 성능을 분석하였다. JBSTC는 MIMO(Multi-Input Multi-Output) 송수신 시스템 채널 모델링을 기반으로 송신측 안테나간 상호 상관 행렬과 수신측 안테나간 상호 상관 행렬을 이용하여 송수신 빔형성기의 안테나 가중치들을 계산한다. 본 논문에서 제안하는 JBSTC 방식은 송수신단에서 발생하는 안테나 간격과 각퍼짐에 따른 상호 상관 값을 효과적으로 보정함으로써 기존의 수평적 시공간 부호화 기법보다 우수함을 알 수 있다.

• Journal of information and communication convergence engineering
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• 제6권3호
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• pp.353-357
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• 2008

One objective in developing the next generation of wireless communication systems is to increase data rates and reliability. A promising way to achieve this is to combine multiple-input and multiple-output signal processing with a space-time coding scheme, which offers higher coding and diversity gains and improves the spectrum efficiency and reliability of a wireless communication system. It is noted, however, that time delay differences and phase differences among different channels increase symbol interference and degrade system performance. In this letter, we investigate phase differences and their effects on multiple-input and multiple-output systems, and propose a compensation algorithm for the Rayleigh fading model to minimize their effects.