• Proceedings of the IEEK Conference
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• 2001.06d
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• pp.45-48
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• 2001

Unequal Error Protection(UP) is reasonable scheme in transmission of compressed video with low bit rate. Because it offers the error correction ability each other data according to the Source Significance Information. Hence it can also be flexible to the given channel environment on the video transmission. This paper propose the joint source channel coding through the UEP in consideration of the hierarchical structure of H.263+ based video and the influence of the transmission error. It especially proposes the error-resilient video transmission technique which can reduce complexity of channel coder & decoder by partitioning the video data with a frame. As the result of the proposed algorithm, it is possible to increase the quality of reconstructed video in the error environment without creating additional bits.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2001.11b
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• pp.109-113
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• 2001

최근 들어 디지털 이동통신 시스템은 음성 통신 뿐만 아니라 멀티미디어 통신에도 그 적용범위를 확장시키고 있다. 그러나 이러한 시스템에서 한정된 채널 대역폭의 사용은 멀티미디어 정보의 대용량성을 고려할 때, 그 적용범위를 심각하게 축소시키는 가장 큰 제한요소이다. 일반적인 통신 시스템의 소스 부호화기는 채널 잡음을 고려하지 않고 설계되며, 채널 부호화기는 소스 신호의 특성과 무관하게 채널 환경의 극복에만 중점을 두고 설계된다. 그러나 대역폭 제한적인 통신 환경에서 보다 효율적인 대역폭 사용을 위해서는 채널 환경에 따라 소스 부호율과 채널 부호율을 가변적으로 운용하여야 한다. 본 논문에서는 영상을 부대역 부호화하여 각 부대역 영상이 원래의 영상 재구성에 기여하는 중요도에 따라 한정된 채널 자원을 최적으로 할당하는 공동 소스/채널 부호화(Joint Source-channel Coding)에 관하여 연구하였다. 부대역 영상의 소스 부호화로는 DPCM과 PCM을 사용하였고, 채널 부호화는 TCM 부호화기를 사용하였으며 상이오류보호(Unequal Error Protection)를 위해 3가지 채널 부호율에 따라 각각 TCQPSK, TC8PSK, TC16PSK 변조방식을 사용하였다. 모의실험에 사용된 채널 환경은 랜덤잡음 환경과 이동수신의 경우에 발생하는 Rayleigh 페이딩 환경을 고려하였으며, 각 환경에서의 채널 SNR에 따라 동일오류보호(Equal Error Protection) 시스템과 상이오류보호(Unequal Error Protection) 시스템의 성능을 비교하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.6
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• pp.471-478
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• 2013

Powerful error control and increase in the number of bits per symbol should be provided for future high-quality communication systems. Each message bit may have different importance in multimedia data. Hence, UEP(unequal error protection) may be more efficient than EEP(equal error protection) in such cases. And the LDPC(low-density parity-check) code shows near Shannon limit error correcting performance. Therefore, the effect of UEP with LDPC codes is analyzed for high-quality message data in this paper. The relationship among MSE(mean square error), BER(bit error rate) and the number of bits per symbol is analyzed theoretically. Then, total message bits in a symbol are classified into two groups according to importance to prove the relationship by simulation. And the UEP performance is obtained by simulation according to the number of message bits in each group with the constraint of a fixed total code rate and codeword length. As results, the effect of UEP with the LDPC codes is analyzed by MSE according to the number of bits per symbol, the ratio of the message bits, and protection level of the classified groups.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.7A
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• pp.960-966
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• 2000

It is essential to develop the robust video transmission system over wireless channel, since the effect of the noise and the interference to compressed video may be fatal. In this paper, we have designed turbo code, which is adequate for the transmission of video and analyzed the performance of that. Especially, we have focused the rate compatible punctured turbo(RCPT) code, which has rate compatible(RC) property for unequal error protection(UEP). It has been shown through computer simulation that the turbo code with helical interleaver yields better performance than those with other interleavers when the size of the interleaver is not large.

• Journal of the Korean Statistical Society
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• v.34 no.4
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• pp.297-309
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• 2005

We consider 'efficiency versus privacy-protection' problem concerned with several well-known randomized response (RR) devices to estimate pro­portion of people bearing a stigmatizing characteristic in a community. The literature of RR on respondent's privacy protection discusses only about response specific jeopardy measures. We propose a measure of jeopardy that is independent of the RR offered by the interviewee and recommend it for using as a technical characteristic of the RR device. For ensuring better cooperation from the interviewees this new measure that depends only on the design parameters of the RR devices may be disclosed to the respondents before producing the RR by implementing the randomization device.

• Journal of Broadcast Engineering
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• v.14 no.5
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• pp.561-572
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• 2009

In this paper, we propose an efficient layer-separable PES packetization and processing scheme for DVB-S2 satellite broadcasting service based on SVC video. Unlike the conventional single layer-based video coding such as MPEG-2, MPEG-4 and H.264, SVC can combine numerous number of video layers, which are aggregated to a single bitstream. Therefore, it is necessary to devise a new PES packetization scheme that can efficiently separate multiple video layers of SVC. In order to combine the layered characteristics of the SVC video and the robust channel coding capability of LDPC (Low Density Parity Check) of DVB-S2 for unequal error protection, we propose an efficient PES packetization in the transmitter side and PES packet processing scheme in the receiver side of DVB-S2. We prove the effectiveness of the proposed scheme in terms of processing speed and time delay required for processing of the separated layers of SVC video in the satellite broadcasting service.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.173-176
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• 2000

The fact that the channel coding methode with property of the source coder is better than using the channel characteristics is well known. In this paper We propose the UEP channel coding scheme using IP-SCCC and DCT-based embedded coder for image transmission. Moreover, to evaluate the effectiveness of the proposed scheme some simulation results are presented, in which the channel models of additive white Gaussian noise and Rayleigh fading are assumed.

• ETRI Journal
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• v.35 no.6
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• pp.1068-1074
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• 2013

This paper proposes an additional forward error correction (FEC) layer to compensate for the defectiveness inherent in the conventional FEC layer in the Long Term Evolution specifications. The proposed additional layer is called a graceful degradation (GD)-FEC layer and maintains desirable service quality even under burst data loss conditions of a few seconds. This paper also proposes a non-delayed decoding (NDD)-GD-FEC layer that is inherent in the decoding process. Computer simulations and device-based tests show a better loss recovery performance with a negligible increase in CPU utilization and occupied memory size.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.7
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• pp.398-400
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• 2014

In this letter, we propose a cross-layer technique jointly considering modulation coding schemes (MCSs) of medium access control (MAC) layer, source significance information (SSI) and error concealment unit of application (APP) layer, and channel quality information (CQI) of physical (PHY) layer. We demonstrate the improved video quality by the proposed technique when H.264 videos are streamed over Rayleigh fading wireless channels.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.71-74
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• 1999

본 논문에서는 이동 무선 채널에 의한 동영상의 실시간 전송을 위해 채널 상태에 따라 터보코드의 반복 복호 횟수를 자동으로 결정한 UEP(Unequal Error Protection) 채널 부호화 방법에 대해 레일리 페이딩 채널에서의 성능을 분석한다. 이 부호화 방법은 열악한 채널 환경에서 우선 순위가 높은 정보에 보다 많은 반복 횟수가 부과되게 함으로써 헤더 정보나 움직임 벡터 등과 같이 동영상 신호의 복원에 중요한 정보에 대한 오류의 전파효과를 억제시킬 수 있다. 연집 오류의 주요인인 레일리 페이딩 채널에서 복호기의 성능을 분석하기 위해 컴퓨터 모의실험을 수행해 그 결과를 제시한다.