• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.11
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• pp.2067-2080
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• 1994

Recently, joint blind equalization and carrier recovery for digital mobile transmission system is of growing interest. In this paper, we describe new receiver structure of joint godard blind equalizer and various recovery loop for QAM modulated signal. After a brief review of Godard blind equalizer and MAP estimation Costas loop, Generalized Costas loop, Leclert loop, Angular form loop, we present two kinds of receiver structures for joint blind equalization and carrier recovery. Using a Monto Carlo simulation technique, we can confirm that two kinds of receiver structures operate very well in the steady state.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1219-1225
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• 2001

In this Paper we describe the design of synchronization algorithms for burst QPSK receiver, which are applicable to BWLL uplink. The demodulator consists of digital down converter, matched filter and synchronization circuits. For symbol timing recovery we ufo Gardner algorithm. And we use forth power method and decision directed method for carrier frequency recovery and phase recovery, respectively. For the sake of performance analysis, we compare simulation results with the board implemented by FPGA which is APEX20KE series chip for Alter. The performance results show it works quite well up to the condition that a frequency offset equal to 4.7% of symbol rate.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.1048-1051
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• 1997

본 논문에서는 GPS 수신기를 이용하여 송전선 양단에 설치되어 있는 전류차동계전기들의 전류샘플링을 동기시키는 방법을 제안하고, 이를 이용한 전류샘플링 동기장치의 개발에 대해 설명 한다. 송전선 양단의 GPS 수신기들에서 만들어지는 서로 동기된 IPPS신호들을 이용해 샘플링 동기신호를 만들어 주고, 이를 이용해서 서로 동기된 전류샘플링이 적당한 계수값 지정과 함께 이루어지도록 A/D변환기와 메모리 그리고 프로그램형 논리 소자를 사용한다. 샘플링 동기신호를 만들어주기 위해서 GPS수신기와 10MHz발진기를 이용한 디지털 위상잠금회로(DPLL, Digital Phase- Locked Loop)를 구성 한다. 본 논문에서 제안하는 전류샘플링 동기방식은 통신을 이용한 기존의 방식에 비해 계전기의 계산부담을 덜어주고 보다 정확한 샘플링 동기를 얻을 수 있게 한다.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.5
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• pp.12-20
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• 1999

본 논문에서는 DVB-T (digital video broadcasting-terrestrial) 수신기의 동기화 알고리듬과 각 동기단 사이의 연동 알고리듬을 제안한다. OFDM( orthohonal frequency division multiplexing) 수신단에서는 프레임 동기, 반송파 동기, 심볼 타이밍 동기가 요구되어진다. 기존의 반송파 동기 방법은 부반송파 간격의 정수배 주파수 옵셋 보상 후 잔존해 있는 주파수 옵셋이 -0.5×(부반송파 간격) 혹은 +0.5×(부반송파 간격)에 가까운 값을 가질 때 많은 시간이 소요되는 문제점을 가지고 있다. 본 논문에서는 시스템의 복잡도를 그대로 유지 하면서 초기 동기화 시간을 줄일 수 있는 반송파 동기 알고리듬을 제안한다. 그리고 DVB-T모드를 추정하는 알고리듬을 제안하고 반송파 동기 추적루프와 심볼 타이밍 동기 추적루프를 동시에 동작시킴으로써 초기 동기화 시간을 추가적으로 줄일 수 있는 심볼 타이ALD 동기 알고리듬을 제안한다. 그리고 전체 수신기 모델의 연동 방안을 제시한다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.6 s.360
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• pp.1-7
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• 2007

This paper proposes CMOS semi-digital data recovery with 2X converse oversampling to reduce power consumption and chid area of high definition multimedia interface (HDMI) receivers. Proposed recovery can reduce its power and the effective area by using nt converse oversampling algorithm and semi-digital architecture. Proposed circuit is fabricated using 0.18um CMOS process and measured results demonstrated the power consumption of 14.4mW, the effective area of $0.152mm^2$ and the jitter tolerance of 0.7UIpp with 1.8V supply voltage.)

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.12C
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• pp.1029-1034
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• 2010

For All Digital QPSK receivers, a phase recovery scheme is required to fix the arbitrarily rotated I/Q quadrature signals due to the transmission path and clock mismatch between the transmitter and the receiver. The conventional Costas phase recovery loop scheme requires a separate AGC(Automatic Gain Control) to obtain the performance independent of input signal power. This paper proposes a simple scheme which separates the phase and amplitude of the input signal via CORDIC algorithm and performs the phase recovery and amplitude compensation simultaneously. The proposed scheme can considerably reduce the logic resources in hardware implementation, has been verified by C++ and Model Sim simulations.

• Journal of Broadcast Engineering
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• v.8 no.2
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• pp.126-135
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• 2003

To investigate the DTV coverage especially in downtown areas and improve the performance of DTV receivers, it is necessary to capture the receiving DTV signals that contain the complex characteristics of the real-world RF environments and regenerate them in a laboratory without the performance degradation. In this paper, we developed a DTV RF capture and regeneration system adapting digital signal processing and high speed hard disk storage techniques and analyze its characteristics. The system can capture and replay the DTV RF signals based on a real-time condition in a hard disk. There Is no time limit for capturing RF data within the installed storage capacity. We can expect various Possible applications for this system such as a tool for the development of the receiver performance analysis, design and analysis for the DTV coverage areas, etc.

• Korean Business Review
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• v.18 no.2
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• pp.133-149
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• 2005

DAB is meeting with mixed success. Denmark is performing similarly to the UK thanks to the innovation of the public broadcaster but where DAB is not so strong, the problem can usually be pointed at the lack of enabling regulation. The UK's example, whilst not appropriate everywhere, has valuable lessons including licensing incentives for existing analogue commercial broadcasters and a market-building obligation on the national multiplex licensee. Despite the obvious success of DAB, it would be an omission to leave some of the continued criticisms unanswered, whether of its slow start or the underlying technology. True, there was much over-optimism in the mid-1990s, coupled with unrealistic promises and expectations of receiver pricing and consumer take-up. Governments across Europe have legislated for DAB digital radio in a variety of ways but few as successfully as the UK. It is essential that both public and private broadcasters are encouraged equally to participate in digital radio. The UK is fortunate because, for the last 10 years, there has been a progressive government policy towards digital broadcasting. The 1996 Broadcasting Act set out a full licensing regime for both digital television and digital radio. The 1996 UK legislation contained a number of key elements which have been cornerstones of its success. DAB digital radio began test broadcasting around ten years ago but it has not been a universal consumer success across Europe. In the UK, however, digital radio receivers are one of the fastest-selling consumer electronics products and sales have overtaken those of analogue radios. Why has the UK succeeded with DAB digital radio when other European countries have yet to see their markets take off? This article explains what steps the UK took to make DAB digital radio a success.

• Convergence Security Journal
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• v.15 no.2
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• pp.3-9
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• 2015

The development of the digital compression technology and the broadcasting receiver's processing power make it possible to apply a multi-view function to the broadcasting services. The multi-view function is usually utilized to provide simultaneously several programs to viewers or to implement a multi-angle service of a sports program that allows a viewer to choose a video of his/her prefer viewpoint. The paper proposes an integrated method for utilizing a multi-view function in the digital broadcasting environment in which more than 100 programs are on air and there may be various data services which want to use multi-view video clips. For the purpose, a method of composing and transmitting multi-view videos and related information has been devised and a Java API to utilize the rapid editing function of a decoding chip-set has been implemented to clip, resize, and display parts of the multi-view videos.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.3
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• pp.212-217
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• 2016

The S-band receiver for Low Earth Orbit satellite is designed and fabricated as engineering model. Demodulator is implemented by using FPGA for extension of demodulator method. The receiver consists of RF Block, Digital demodulator and Power stage and has a Doppler tracking function to compensate a frequency shift that occur on the operation. The measured results of fabricated receiver show BER of less than $1.0{\times}10^{-6}$ at -110dBm RF input power and equipped a frequency tracking of ${\pm}100KHz$ relative to the center frequency. TID test was satisfied with the results of the test criterion is 10krad.