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Manager
조회 25033
Status : | Presented |
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Date : | 1992-07 |
Title : | 디지털 이동 통신에서 trellis-부호화된 π/8-shift 8psk 변조 방식 성능 분석 |
Authors : | 강창언, 홍대식, 황인태, 김종일 |
Conference : | 한국통신학회 하계 종합 학술발표회 11권 1호 |
Abstract : | In this thesis, discussion on the performance of the π/4-shift QPSK method which is one appropriate method of modulation and demodulation in digital mobile communication systems under a severe fading channel has been made. The π/8-shift 8PSK trellis-coded method has been suggested through the TCM(Trellis-Coded Modulation). and has been used for performance improvement. Including the TCM in the π/4-shift QPSK modulating method, the coding gain has been calculated by obtaining the same required bandwidth, transmitted power, data rate and also by combining the coding and modulation scheme. To estimate the improved π/8-shift 8PSK method system performance in the trellis-coded mobile communication channel, the system has been modeled for two cases of fading rates, 10Hz and 30Hz, with the Doppler effect for the varing mobile velocity under a channel that has the Rayleigh fading effect and additive white Gaussian noise. The bit error probability has been used to analyze the coding gain of the trellis-coded π/8-shift 8PSK. To compare the improved performance of the original system and the new modeled system, the TCM state number has been changed to 4,8, and 16. and each case has been calculated individually. As a result, when the state number has been increased, a more improved performance is obtained. The trellis-coded π/8-shift 8PSK shows obvious improvement when it is compared to the established π/4-shift QPSK. An 1 to 4 dB coding gain has been obtained in the additive white Gaussian noise channel and a 3 to 15 dB coding gain has been obtained in the Rayleigh fading channel. |
URL : | http://mirinae.yonsei.ac.kr//?module=fil...7acf3972f0 |
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2023.09 Sunday Monday Tuesday Wednesday Thursday Friday Saturday 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
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2023.09 Sunday Monday Tuesday Wednesday Thursday Friday Saturday 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30