• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2002.11a
• /
• pp.197-200
• /
• 2002

디지털 오디오 방송은 안정적이고 넓은 범위의 소스코딩 및 채널코딩 기능을 수행하고, 다양한 압축 기능 등을 제공함으로써, 기존의 아날로그 방송에서는 불가능했던 많은 부가 데이터 서비스들의 출현을 가능하게 하였다. 본 논문에서는 Eureka-147 디지털 오디오방송 시스템의 운용자, 특히, 다중화 사업자 또는 네트워크 제공자의 입장에서 다양한 전송용량을 요구하는 데이터 서비스들이 혼재하는 통계적 상황을 모델링하여 분석하여 보고, 앞으로 디지털 오디오 방송을 이용하는 데이터 응용 서비스가 활성화 될 경우, 이들의 효율적인 관리 방법을 검토하여 보았다.

• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2003.06a
• /
• pp.197-200
• /
• 2003

본 논문에서는 IEEE 802.11a 무선 LAN 용 CODEC 회로를 설계하고, VHDL 코딩과 FPGA에 의한 회로설계 검증에 관해 기술한다. IEEE 802.lla WLAN CODEC의 구조는 크게 데이터 보호를 위한 스크램블러/디스크램블러, 채널 에러에 대한 정보보호를 위한 Convolutional 부호기와 Viterbi 복호기로 구성된 채널 코덱, 그리고 연집에러를 랜덤 에러로 변화시키는 인터리버/디인터리버로 구성된다. 본 논문에서는, 이와 같은 CODEC의 각 부분을 하드웨어로 구현하기 위한 새로운 회로구성을 제안하고, 그 성능을 VHDL 코딩에 의한 시뮬레이션과 FPGA에 의한 하드웨어 검증 결과를 제시한다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.04d
• /
• pp.442-444
• /
• 2003

본 논문에서는 IEEE 802.113 무선 LAN 용 CODEC 회로를 설계하고, VHDL 코딩 과 FPGA에 의한 회로설계 검증에 관해 기술한다. IEEE 802.11a WLAN CODEC의 구조는 크게 데이터 보호를 위한 스크램블러/디스크램블러, 채널 에러에 대한 정보보호를 위한 Convolutional 부호기와 Viterbi 복호기로 구성된 채널 코덱, 그리고 연집에러를 랜덤 에러로 변화시키는 인터리버/디인터 리버로 구성된다. 본 논문에서는, 이와 같은 CODEC의 각 부분을 하드웨어로 구현하기 위한 새로운 회로구성을 제안하고, 그 성능을 VHDL 코딩에 의한 시뮬레이션과 FPGA에 의한 하드웨어 검증 결과를 제시한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.5
• /
• pp.91-103
• /
• 2015

This paper presents "The 3-User NOR switching channel based on interference decoding with receiver cooperation" in succession to "Jeju Jong Nang channel code I, II". The Jeju Jong Nang code is considered as one of the earliest human binary coded communication (HBCC) in the world with a definite "1" or "0" binary symbolic analysis of switching circuits. In this paper, we introduce a practical example of interference decoding with receiver cooperation based on the three user Jong Nang NOR switching channel. The proposed system models are the three user Jong Nang (TUJN) NOR logic switching on-off, three-user injective deterministic NOR switching channel and Gaussian interference channel (GIC) with receiver cooperation. Therefore, this model is well matched to Shannon binary symmetric and erasure channel capacity. We show the applications of three-user Gaussian interference decoding to obtain deterministic channels which means each receiver cooperation helps to adjacent others in order to increase degree of freedom. Thus, the optimal sum rate of interference mitigation through adjacent receiver cooperation achieves 7 bits.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.05a
• /
• pp.54-56
• /
• 2015

In this paper, we investigate a physical-layer network coding (PNC) in a two-way relay channel (TWRC) where two sources send and receive data with each other by help of a relay node with multiple antennas. We focus on the multiple-access phase of the TWRC in this paper. It is assumed that the source nodes do not know the wireless channel and the wireless channel independently varies in time, that is, fast fading environments. At the relay node, the channel is assumed to be perfectly known. The relay node utilizes the channel sate information and applies maximum likelihood ratio for detecting received signals. Through extensive simulations, it is shown that a bit error rate (BER) performance becomes improved as the number of antennas at the relay node increases.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.3A
• /
• pp.197-204
• /
• 2009

Cyclic delay diversity (CDD) is considered a simple approach to exploit the frequency diversity, to improve the system performance in orthogonal frequency division multiplexing (OFDM) systems. Also, the linear preceding technique can significantly improve the performance of communication systems by exploiting the channel state in formation (CSI). In order to achieve enhanced performance, we propose applying linear preceding to the conventional CDD-OFDM transmit diversity schemes over Rayleigh fading channels. The proposed scheme works effectively with the accurate CSI in time-division-duplex (TDD) OFDM systems with CDD, where the reciprocity is ass umed instead of channel state feedback. For a BER of $10^{-4}$ and the mobility of 3 km/h, simulation results show that a gain of 6 dB is achieved by the proposed scheme over both flat fading and Pedestrian A (Ped A) channels, compared to the conventional CDD-OFDM system. On the other hand, for a mobility of 120 km/h, a gain of 2.7 dB and 3.8 dB is achieved in flat fading and Vehicular A (Veh A) channels, respectively.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.04a
• /
• pp.586-588
• /
• 2004

트랜스코딩에 관련된 연구들은 비디오 스트리밍에 대한 품질관련 연산들을 제공해 주었으나 트랜스코딩 과정에서 발생하는 연산지연과 전송지연에 대한 고려가 부족하였다. 또한 비디오 스트리밍에 대한 캐슁기법과 관련된 연구들은 비디오 스트리밍 서버와 클라이언트 사이의 전송지연을 줄여주는 장점을 제공하는 반면, 트랜스코딩과의 협업을 위한 연동들은 드물었다. 본 논문에서는 대역폭이 유선망에 비해 상대적으로 빈약한 무선망 채널을 통해 연속적인 비디오 스트리밍 서비스를 제공하는 과정 중에 발생하는 전송지연과 연산지연을 동시에 극복할 수 있도록 해주는 통합 시스템 아키텍처와 캐슁 알고리즘을 제안한다.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.8
• /
• pp.3-14
• /
• 2013

We demonstrate a fashion of quantum channel combining and splitting, called polar quantum channel coding, to generate a quantum bit (qubit) sequence that achieves the symmetric capacity for any given binary input discrete quantum channels. The present capacity is achievable subject to input of arbitrary qubits with equal probability. The polarizing quantum channels can be well-conditioned for quantum error-correction coding, which transmits partially quantum data through some channels at rate one with the symmetric capacity near one but at rate zero through others.

• Information and Communications Magazine
• /
• v.14 no.9
• /
• pp.170-187
• /
• 1997

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.10
• /
• pp.3290-3299
• /
• 2000

Digital watermarking has similar concepts with channel coding thechnique for transferring data with minimizing error in noise environment, since it should be robust to various kinds of data manipulation for protecting copyrights of multimedia data. This paper proposes a digital watermarking technique which is robust to various kinds of data manipulation. Intellectual property rights information is encoded using a convolutional code, and block-interleaving technique is applied to prevent successive loss of encoded data. Encoded intelloctual property rithts informationis embedded using spread spectrum technique which is robust to cata manipulation. In order to reconstruct intellectual property rights information, watermark signalis detected by covariance between watermarked image and pseudo rando noise sequence which is used to einbed watermark. Embedded intellectual property rights information is obtaned by de-interleaving and cecoding previously detected wtermark signal. Experimental results show that block interleaving watermarking technique can detect embedded intellectial property right informationmore correctly against to attacks like Gaussian noise additon, filtering, and JPEG compression than general spread spectrum technique in the same PSNR.