基於軟性中繼處理的壓縮傳送系統

A Study of Soft Information Relaying for Compress-and-Forward Systems

曾怡華(I-Hua Tseng)

指導教授 ： 張文輝

國立交通大學/電機學院/電信工程系所/碩士(2013年)

https://doi.org/10.6842/NCTU.2013.00297

摘要

本論文針對二位元均勻分布擬亂訊源，利用低密度奇偶查核碼具體實現合作式通訊的壓縮-傳送機制。合作式通訊系統旨在建構一虛擬的多天線系統，有效運用其空間多樣性以對抗通道雜訊。相較於傳統的放大-傳送及解碼-傳送機制，壓縮-傳送機制是利用中繼端將訊源端傳送的訊號經解碼所得的軟性訊息，進行量化或估計後傳送至目的端。基於低密度奇偶查核碼的良好錯誤更正能力，本篇論文以低密度奇偶查核碼實現壓縮-傳送機制，針對中繼端硬性位元及軟性位元的兩種模式進行模擬分析。實驗結果顯示基於軟性中繼處理的合作式壓縮-傳送機制可有效對抗通道雜訊的干擾。

關鍵字

合作式通訊 ； 壓縮傳送 ； 軟性中繼處理 ； 低密度奇偶查核碼

並列摘要

In this thesis, we study the use of low-density parity check (LDPC) codes for the compress-and-forward systems. Cooperative communication has been shown effective in building a virtual multiple-antenna system which exploits the spatial diversity. Unlike the conventional amplify-and-forward (AF) and decode-and-forward (DF), thecompress-and-forward (CF) uses the relay to perform soft decoding of the received source signals , and then forwards the quantized/estimated soft information to the destination. In this thesis, we exploit the good error-correcting capability of low-density parity check codes for the compress-and-forward scheme in conjunction with the relaying based on hard bits or soft bits. Simulations show that the proposed soft information relaying scheme can outperform traditional CF scheme.

並列關鍵字

cooperative communication ； compress-and-forward ； soft information relaying ； low-density parity check code

參考文獻

[19] 王韋超，「基於低密度奇偶查核碼的分散式訊源編碼機制」，國立交通大學碩士論文，民國一百零一年。

[1] T. M. Cover and A. A. El Gamal, “ Capacity Theorems for the Relay Channel, ” IEEE Trans. Inform. Theory, Vol. IT-25, pp. 572-584, Sept. 1979.

[2] R. G. Gallager, “Low-Density Parity-Check Codes,” Cambridge, MA: MIT Press, 1963.

[4] G. A. Margulis, “Explicit Construction of Graphs without Short Cycles and Low Density Codes,” Combinatorica, vol. 2, no. 1, pp. 71–78, 1982.

[5] R. M. Tanner, “A Recursive Approach to Low Complexity Codes,” IEEE Trans. Inf.Theory,vol. IT-27, no. 5, pp. 533–547, Sep. 1981.