http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
ATSC 3.0 시스템을 위한 부트스트랩 신호를 이용한 동기 방식 연구
김정창(Jeongchang Kim),김형석(Hyeongseok Kim),박성익(Sung Ik Park),김흥묵(Heung Mook Kim) 한국방송·미디어공학회 2016 방송공학회논문지 Vol.21 No.6
In ATSC 3.0 systems, a bootstrap signal is located at the start of each frame. In this paper, we propose an initial synchronization scheme for ATSC 3.0 systems using the bootstrap signal. The bootstrap signal of ATSC 3.0 has several repetition patterns in the time domain. By utilizing the repetition patterns within the bootstrap, the proposed scheme can obtain an initial synchronization at the receiver. Also, simulation results show that the proposed scheme can obtain an initial synchronization at very low signal-to-noise ratios.
김정창(Jeongchang Kim),박성익(Sung Ik Park),김흥묵(Heung Mook Kim) 한국방송·미디어공학회 2015 방송공학회논문지 Vol.20 No.2
In this paper, we model the interference plus noise signal for terrestrial cloud transmission systems and present bit error rate (BER) performances. Since terrestrial cloud transmission systems experience co-channel interference from one or more transmitters, they have to operate under a negative signal-to-interference plus noise ratio (SINR) region. The interference plus noise signal can be modeled as Gaussian random variable under the required SINR region and we observe the BER performance of the cloud transmission system using the derived model. Also, we propose an improved channel estimation scheme by averaging the channel estimates based on least square based interpolation scheme. Simulation results show that the cloud transmission system can operate under negative SINR region using the proposed channel estimation scheme.
Rate-2인 2×2 시공간 부호를 위한 효율적인 복호 알고리즘
김정창(Jeongchang Kim),전경훈(Kyungwhoon Cheun) 대한전자공학회 2009 電子工學會論文誌-TC (Telecommunications) Vol.46 No.3
최근에 간단한 ML 복호가 가능한 rate-2, 2×2 시공간 부호가 개발되었다. 비록 이러한 간단한 ML 복호 알고리즘이 ML 복호 복잡도를 줄여 주지만 여전히 향상될 여지가 남아 있다. 본 논문에서는 간섭제거 방법을 사용하여 ML 복호와 거의 동일한 성능을 가지면서 rate-2, 2×2 시공간 부호를 위한 효율적인 복호 알고리즘을 제안한다. 제안된 알고리즘의 복호 복잡도는 기존의 간단한 ML 복호에 비해서도 더욱 감소하며 변조 차수가 클수록 복호 복잡도 감소율은 더욱 증가한다. Recently, a rate-2, 2×2 space-time code with simple ML decoding has been designed. Though the simple ML decoding algorithm does reduce the ML decoding complexity, there is still need for improvement. In this paper, we propose an efficient decoding algorithm for the rate-2, 2×2 space-time code using interference cancellation techniques with performance virtually identical to that of ML decoding. Also, the decoding complexity of the proposed algorithm is significantly reduced compared to the conventional simple ML decoding, especially for large modulation orders.
김정창(Jeongchang Kim),전경훈(Kyungwhoon Cheun) 대한전자공학회 2009 電子工學會論文誌-TC (Telecommunications) Vol.46 No.3
본 논문에서는 수신기에서 채널 추정을 필요로 하지 않는 MWSK (M-ary orthogonal Walsh sequence keying)를 적용한 ST-MWSK (space-time MWSK)를 제안한다. ST-MWSK의 noncoherent ML (maximum-likelihood) 검출기의 계산 복잡도는 기존의 ST-FSK (ST frequency-shift keying) 방식에 비해 크게 줄어든다. 또한 ST-MWSK는 ST-FSK와 거의 동일한 성능을 나타낸다. In this paper, we propose ST-MWSK (space-time M-ary orthogonal Walsh sequence keying) employing MWSK, which does not require channel estimation at the receiver. The computational complexity for the noncoherent ML (maximum-likelihood) detector of ST-MWSK is significantly reduced compared to that of ST-FSK (ST frequency-shift keying). Also, the performance of ST-MWSK is virtually identical to that of ST-FSK.