臺灣博碩士論文加值系統

在文獻中已經指出，相較於使用同一位元映射規則於同一封包的多次傳輸，
改變多次傳輸的位元映射規則可以提供更高的吞吐量。根據位元交錯編碼調變的
通道容量分析，重傳時的位元映射規則必須隨著所操作的通道訊雜比的改變而改變。因此我們提出了使用基因演算法找出對每個訊雜比而言最好的位元映射規則。而當位元交錯編碼調變迭代解碼用在混合自動重傳機制時，由外來資訊轉換圖的分析也可得知，對同一編碼方式而言，每個不同的訊雜比也應該有不同的位元映射規則。因此我們在無限長度封包與無限迭代次數的假設下，針對每個訊雜比設計出最佳的位元映射規則。而在實際有限長度封包的應用下，我們畫出了解映射器與解碼器轉換圖相對於平均值的變動，同時建議在解映射器與解碼器的轉換圖之間保留一些空間來設計有限長度封包的位元映射規則。

It has been shown in the literature that varying bit-to-symbol mappings for multiple transmissions of the same packet provides better throughput performance compared to using the same bit-to-symbol mapping throughout all the transmissions. The analysis of BICM capacity suggests that the retransmission mapping scheme should be adaptive to the operating SNR. Hence we propose using a genetic algorithm to find the optimal mapping for each SNR. When BICM with iterative decoding (BICM-ID) is applied in HARQ systems, the analysis of EXIT-chart also suggests that the suitable mapping for each SNR for the same code should be different. Therefore, we find optimal mapping for each SNR under the assumption of infinite block length and unlimited iteration number. In the real application of finite block length, we plot the variation of demapper and decoder transfer curve relative to the averaged one and suggest that margins between the demapper and the decoder transfer curve should be preserved for the finite block length design.

摘要 iii
Abstract iv
誌謝 v
Content vi
List of Tables viii
List of Figures ix
Chapter 1: Introduction 1
Chapter 2: Overview of HARQ 5
Chapter 3: System Model 8
3.1 Transmitter 8
3.2 Channel 9
3.3 Receiver 9
3.3.1 BICM Receiver Model 10
3.3.2 BICM-ID Receiver Model 10
3.3.3 Joint MAP Demapper 11
Chapter 4: Symbol Mapping Diversity in HARQ 13
4.1 Constellations under joint detection 13
4.2 Coded Modulation Capacity 16
4.3 Bit-Interleaved Coded Modulation Capacity 23
Chapter 5: Extrinsic Information Transfer Chart 28
5.1 Transfer characteristics 28
5.2 Transfer Characteristics of the Demapper 31
5.2.1 Demapper Transfer Function 31
5.2.2 Properties of the demapper transfer function 34
5.2.2.1 Area property 34
5.2.2.2 Zero prior characteristics 36
5.2.2.3 Summaries of the Properties of the Demapper Transfer Curve 37
5.2.2.4 Some Examples of Demapper Transfer Curve 38
5.3 Transfer Characteristics of Decoder 40
5.4 Extrinsic Information Transfer Chart (EXIT Chart) 43
Chapter 6: Mapping Design Criterion for BICM in HARQ 45
6.1 Motivation 45
6.2 Design Criterion 47
Chapter 7: Mapping Design Criterion for BICM-ID in HARQ 48
7.1 Motivation 48
7.2 Design Criterion For infinite Block Length 50
7.3 EXIT chart for Finite Block Length 51
7.4 Distribution of Output Extrinsic Mutual Information 54
7.5 Design Criterion for finite block length 56
Chapter 8: Search Algorithm 57
8.1 Simplified Model 57
8.1.1 Hard-decision Virtual Channel 57
8.1.2 Extrinsic Channel 60
8.1.3 Closed Form Demapper Transfer Function 61
8.2 Genetic Algorithms 62
8.2.1 Introduction 62
8.2.2 General Procedure 64
8.2.3 Representation Scheme 65
8.2.4 Selection 66
8.2.5 Crossover 66
8.2.6 Mutation 67
8.2.7 Suggested GA Parameters 68
8.2.7.1 Population Size 68
8.2.7.2 Elite Number 69
8.2.7.3 Crossover Probability 70
8.2.7.4 Mutation Probability 71
8.2.7.5 Summary of the Suggested GA Parameters 72
Chapter 9: Mapping Search Results 73
9.1 Mappings for BICM 73
9.2 Mappings for BICM-ID with infinite block length 79
9.3 Mappings for BICM-ID with finite block length 82
Chapter 10: Simulation Results 84
10.1 BICM 84
10.1.1 Turbo Codes 87
10.1.2 Convolutional Codes 92
10.2 BICM-ID 95
10.2.1 Mappings for Infinite Block Length 95
10.2.2 Mappings for Finite Block Length 97
Chapter 11: Conclusions 99
Reference 100

[1] G. Ungerboeck, “Channel coding with multilevel/phase signals,” IEEE Trans. Inform. Theory, vol. 28, pp. 55–67, Jan. 1982.
[2] E. Zehavi, “ 8-PSK trellis codes for a Rayleigh channel,” IEEE Trans. Commun., vol. 40, pp. 873-884, May 1992.
[3] G. Caire, G. Taricco, and E. Biglieri, “Bit-interleaved coded modulation,” IEEE Trans. Inform. Theory, vol. 44, pp. 927-945, May 1998.
[4] X. Li and J. A. Ritcey, “Trellis coded modulation with bit interleaving and iterative decoding,” IEEE J. Select. Areas Commun., vol. 17, pp.715-724,1999.
[5] X. Li, A. Chindapol, and J.A. Ritcey, “Bit-interleaved coded modulation with iterative decoding and 8PSK signaling,” IEEE Trans. Commun., vol.50, no.8, pp.1250–1257, Aug. 2002.
[6] S. ten Brink, “Designing iterative decoding schemes with the extrinsic information transfer chart”, AEU Int. J. Electron Commun., vol. 54, no. 6, pp. 389-398, Dec. 2000.
[7] S. ten Brink, “Convergence Behavior of Iterative Decoded Parallel Concatenated Codes,” IEEE Trans. Comm., vol. 49, no. 10, pp. 1727-1737, Oct. 2001.
[8] Ashikhmin,A., Hramer,G., and ten Brink,S.:” Extrinsic information transfer functions: model and erasure channel properties”, IEEE Trans. Inf. Theory, vol. 50, No.11,pp.2657-2673, Nov. 2004
[9] Qi, X.; Zhou, S.; Zhao, M.; Wang, J., "Design of constellation labeling maps for iteratively demapped modulation schemes based on the assumption of hard-decision virtual channels," Communications, IEE Proc., vol.152, no.6, pp. 1139-1148, 9 Dec. 2005
[10] S. Lin, D. J. Costello Jr., and M. J. Miller, “Automatic-repeat-request error-control schemes,” IEEE Commun. Mag., vol. 22, no. 12, pp. 5–18, Dec. 1984.
[11] S. Lin and D. J. Costello, Jr., “Error Control Coding”. Pearson Prentice Hall, 2003.
[121 D. Chase. "Code combining - a maximum-likelihood decoding approach for combining an arbitrary number of noisy packets." IEEE Trans. Commum. , vol. COM-33. no. 5. pp. 385-393. May 1985.
[13] S. Y. Le Goff, “Signal constellations for bit-interleaved coded modulation,”
IEEE Trans. Inform. Theory, vol. 49, no. 1, pp. 307–313, Jan.2003
[14] L. Szczecinski, F.-K. Diop, and M. Benjillali, “BICM in HARQ with Mapping Rearrangement: Capacity and Performance of Practical Schemes”, GLOBECOM
pp. 1410-1415, NOV 2007
[15] Ch. Wengerter, A. Golitschek Edler von Elbwart, E. Seidel, G. Velev, M.P. Schmitt,” Advanced Hybrid ARQ Technique Employing a Signal Constellation Rearrangement,” IEEE VTC. Porc., vol. 4, Fall 2002.
[16] H. Samra, Z. Ding, and P. M. Hahn “Symbol Mapping Diversity Design for Multiple Packet Transmissions”, IEEE Transactions on Communications, vol. 53, No.5, May 2005. pp. 810-817
[17] J. V. K. Murthy and A. Chockalingam, “Log-likelihood ratio based optimum mappings selection for symbol mapping diversity with M-QAM,” Proc. NCC’2005, Kharagpur, India, January 2005.
[18] L. Szczecinski and M. Bacic, “Constellations design for multiple transmissions : Maximizing the minimum squared Euclidean distance,” in IEEE WCNC 2005, New Orlean, USA, Mar. 2005, pp. 1066 – 1071
[19] M. Gidlund and Y. Xu ”An Improved ARQ Scheme with Application to Multi-Level Modulation Techniques”, ISCIT 2004, Vol. 2, pp.973 - 978 ,Oct 2004
[20] M. N. Khormuji and E. G. Larsson, “Improving collaborative transmit diversity by using constellation rearrangment,” in Proc. IEEE Wireless Commun. and Networking Conf., Hongkong, Mar. 2007
[21] J. Roberson, Z. Ding, “A BICM approach to Type-II Hybrid ARQ,” IEEE ASSP. Conf. Proc. vol.4, May 2006
[22] D. E. Goldberg, “Genetic Algorithms in Search, Optimization, and Machine Learning”, Addison Wesley, 1989
[23] E. K. P. Chong, S.H. Zak, “An Introduction to Optimization”, John Wiley & Sons, 2001