표제지
목차
Abbreviation 9
Abstract 11
제1장 서론 14
제2장 수중 통신에서 고려되는 채널 부호화 기법 19
2.1. 채널 부호화 기법 19
2.1.1. 강판정 기반 부호화 기술 21
2.1.2. 연판정 기반 반복 부호화 기술 30
2.2. 성능 분석기반 최적의 부호화 기법 37
2.2.1. 수중 채널 모델링 및 시뮬레이션 결과 37
2.2.2. Error floor 및 성능 향상을 위한 터보 Pi 부호화 기법 51
제3장 저전력 고속 터보 Pi 복호 알고리즘 57
3.1. Radix-4 알고리즘 57
3.2. Center-to-Top 알고리즘 59
3.3. Early-Stop 알고리즘 59
3.4. 병렬 복호기 알고리즘 60
제4장 SISO 수중채널에서 반복기반의 최적의 복호 구조 63
4.1. 채널 등화 기법 64
4.2. 반복 기반의 터보 등화기 제안 68
4.3. 제안된 반복 기반 터보 등화기의 최적 파라메타 설정 70
4.3.1. 위상 오차에 따른 최적의 패킷 구조 제시 71
4.3.2. 최적의 반복 횟수 분석 77
제5장 MIMO 수중채널에서 계층적 시공간 부호를 이용한 최적의 복호 구조 83
5.1. 시공간 부호화 방식 84
5.1.1. 시공간 블록 부호 84
5.1.2. 시공간 격자 부호 87
5.1.3. 계층적 시공간 부호 89
5.1.4. 성능분석을 통한 최적의 계층적 시공간 부호화 방식 설정 91
5.2. MIMO에서의 채널 등화 기법 93
5.3. 수중환경에서의 최적의 계층적 시공간 복호 구조 제안 96
5.3.1. 시공간 부호화 방식의 강판정 및 연판정에 따른 성능 98
5.3.2. MIMO 수중 환경에 적합한 최적의 등화 기법 99
5.3.3. 반복 기반의 최적의 복호 구조 제안 및 성능 분석 101
제6장 결론 103
참고문헌 106
연구실적 111
Table 2.1. The channel coding method at multi-path charmel environment 20
Table 2.2. The shift register state and output of (2, 1, 3) encoder 23
Table 2.3. The matrix of punctured encoders 26
Table 2.4. The result of eigenray at east sea in april 38
Table 2.5. The parameter for simulation 40
Table 2.6. The comparison of iterative code method 50
Table 2.7. The puncturing pattern of coding rate 1/2, 3/4, 4/5 55
Table 3.1. The algorithm of early-stop 60
Table 3.2. The speed by Eb/No 62
Table 4.1. The Optimal data length in the region of QEF 76
Table 4.2. The signal formation of LFM 79
Table 5.1. The design of efficient STTC code 87
Figure 1.1. The block diagram for underwater communication 15
Figure 2.2. The Trellis diagram of (2, 1, 3) encoder 24
Figure 2.3. The hamming distance of each route 25
Figure 2.4. The general block diagram at concatenated codes system 27
Figure 2.5. The Block diagram of TCM 28
Figure 2.6. The mapping by signal set of 8PSK 29
Figure 2.7. The example of TCM combined with 8PSK 30
Figure 2.8. The structure of Turbo encoder and decoder 32
Figure 2.9. The example of parity check matrix 33
Figure 2.10. The bipartite graph of LDPC 33
Figure 2.11. The decoding process of LDPC 34
Figure 2.12. The Block diagram of cross layer at DVB-S2M 36
Figure 2.13. The structure of MPE-FEC frame 36
Figure 2.14. The SVP and eigenray at east sea 38
Figure 2.15. The delay profile by arrival time of eigenray 39
Figure 2.16. The Block diagram for simulation 39
Figure 2.17. The BER performance of uncoded BPSK at underwater channel 42
Figure 2.18. The BER performance of convolutional code at underwater channel 42
Figure 2.19. The BER performance of turbo code at underwater channel 43
Figure 2.20. The BER performance of LDPC code at underwater channel 43
Figure 2.21. The BER performance of TCM at underwater channel 44
Figure 2.22. The distortion of received signal by multi-path 44
Figure 2.23. The BER performance of RS code at underwater channel 46
Figure 2.24. The BER performace of upper-layer code at cross layer coding method 46
Figure 2.25. The comparison of BER performance by error correcting capacity in RS code 47
Figure 2.26. The BER performance of concatenated code at underwater channel 48
Figure 2.27. The BER performance of cross layer at underwater channel 48
Figure 2.28. The BER performance by channel coding method at underwater channel 49
Figure 2.29. The BER performance of turbo code compared with LDPC code 50
Figure 2.30. The structure of turbo CRSC encoder with input bit m=2 52
Figure 2.31. The relation of finally state with Sc(이미지참조) 54
Figure 2.32. RCS-NG Turbo Pi Encoder 54
Figure 2.33. The comparison of BER Performance by coding rate 56
Figure 3.1. The structure of turbo decoder based on Radix-4 58
Figure 3.2. The decoding process of high speed turbo decoder using center-to-top 59
Figure 3.3. The structure of turbo decoder using parallel mode 61
Figure 4.1. The structure of LMS-DFE 66
Figure 4.2. The structure of turbo equalizer based on iteration 69
Figure 4.3. The structure of packet 71
Figure 4.4. The structure of DD-CPR 72
Figure 4.5. Environment of oceanic experimentation 73
Figure 4.6. The delay profile in the distance of 200 [m] and 500 [m] 74
Figure 4.7. The formation of received signal 75
Figure 4.8. The comparison of received image for the case of applying Turbo Pi scheme 77
Figure 4.9. Measured sound velocity profile 78
Figure 4.10. Experimental setup for sea trials 78
Figure 4.11. Measured channel time-delay profile 79
Figure 4.12. The transmission and received signal at actual survey 80
Figure 4.13. Constellations 81
Figure 4.14. The BER performance of turbo equalizer 82
Figure 5.1. The general MIMO system 83
Figure 5.2. The coding method of Alamouti 85
Figure 5.3. The structure of 2×2 STBC 85
Figure 5.4. The structure of STTC based on 32-state 88
Figure 5.5. The state and trellis diagram at 32-state 89
Figure 5.6. The layered STTC based on proposed efficient iteration 90
Figure 5.7. The BER performance of general layered STTC 91
Figure 5.8. The BER performance of proposed layered STTC 92
Figure 5.9. The structure of LMS-DFE at 32-state STTC 95
Figure 5.10. The general structure using layered STTC and equalizer 96
Figure 5.11. The SVP for MIMO experiment 97
Figure 5.12. The Tx and Rx scheme for experiment 97
Figure 5.13. The delay profile at each channel 98
Figure 5.14. The BER performance by soft decision and hard decision 99
Figure 5.15. The BER performance of layered STTC using equalizer 100
Figure 5.16. The proposed efficient decoding structure based on iteration 101
Figure 5.17. The BER performance of proposed layered STTC 102