結合空時碼與網路編碼的雙向無線網路傳輸

Bi-directional Wireless Communication with Space-time Code and Network Coding

張伊伸(Yi-Shen Zhang)

指導教授 ： 王佳盈

中原大學/工學院/電機工程研究所/碩士(2009年)

https://doi.org/10.6840/cycu200901135

摘要

網路編碼技術允許中間節點將不同輸入訊息作編碼，然後再廣播給鄰近的節點。相較於傳統的網路傳輸，網路編碼能夠提升傳輸效率和可靠度。另一方面，Alamouti所提出的空時區塊碼，也經常被用在無線傳輸上，利用多根天線傳送訊息，以達到更好的傳輸效能。
2008年Chau Yuen 等人提出了一個結合網路編碼與空時碼的傳輸架構，主要目的是為了進一步提升雙向無線傳輸的效能，該論文並針對放大前送(Amplify-and-Forward)與解碼前送(Decode-and- Forward) 的方法，分別在具有和不具有通道訊息狀態 (Channel State Information) 的狀況下做了許多模擬。基本上，其模擬架構中，中繼點有兩根天線，而來源與目的節點各有一根天線。
在本論文中，我們以Chau Yuen的架構為基礎，進一步針對中繼點有三根和四根傳送天線的狀況下，做更進一步的分析與探討。透由實際模擬與分析，我們得知在解碼前送的架構下，可以透過增加中繼點天線的個數而得到更好的傳輸效能。

關鍵字

空時區塊碼 ； 網路編碼 ； 放大前送 ； 解碼前送

並列摘要

Network coding is a technique which allows intermediate nodes to encode the input data before broadcasting the information to other neighbors. Compared with traditional network transmission, it can improve the throughput and reliability of transmission. On the other hand, in order to improve the performances of wireless transmission, Alamouti space-time block code is also widely used. It uses multiple antennas to transmit messages simultaneously to achieve better performances.
In 2008, Chau Yuen, etc., proposed a scheme which combines network coding with space-time code to improve the performances of transmission in bi-directional wireless communication. They analyze Amplify-and-Forward (AF) and Decode-and-Forward (DF) methods with and without channel state information (CSI). The simulations are based on schemes which have two antennas at the relay, and a single antenna at the source and destination.
In this thesis, we make a further analysis and discussion based on Chau Yuen's scheme. We study the schemes which have three or four antennas at the relay. According to our simulations, we conclude that by using multi-antennas in Decode-and-Forward (DF) case, the transmission performances can be further improved.

並列關鍵字

decode-and-forward ； space-time coding ； amplify-and-forward. ； network coding

參考文獻

S. Alamouti, “A simple transmit diversity technique for wireless communications ,” Selected Areas in Communications, IEEE Journal on, vol. 16, 1998, 頁. 1451-1458.

V. Tarokh, H. Jafarkhani, 及 A. Calderbank, “Space-time block coding for wireless communications: performance results,” Selected Areas in Communications, IEEE Journal on, vol. 17, 1999, 頁. 451-460.

Chau Yuen, Woon Hau Chin, Yong Liang Guan, Wenhua Chen, 及 Taoyi Tee, “Bi-Directional Multi-Antenna Relay Communications with Wireless Network Coding,” 2008, 頁. 1385-1388.

P. Popovski 及 H. Yomo, “Wireless network coding by amplify-and-forward for bi-directional traffic flows,” Communications Letters, IEEE, vol. 11, 2007, 頁. 16-18.

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