無線衰落信道中新的切換式和/或選擇式多支分集接收

New Switch and/or Selection Diversity for Wireless Fading Channels

陳耀華(Yao-Hua Chen)

指導教授 ： 趙燿庚

元智大學/電機通訊學院/通訊工程學系/博士(2011年)

https://doi.org/10.6838/YZU.2011.00040

摘要

本論文針對選擇性合成(selection combining, SC) 與切換式合成(switch combining, SWC)提出一種新的架構並對所提出之架構進行效能分析。對於選擇性合成而言，為了降低最佳式選擇性合成(optimal SC, |αr|−SC)在硬體實現上之複雜度，本論文提出了一種利用正規化衰減因子(normalized fading factor)和訊號偵測變數之大小的和來做天線之選擇依據之選擇性合成((α+|r|)−SC)。其中
α是指通道之衰減因子(fading factor)而r 是天線接收之訊號。所提出之(α+|r|)選擇性合成在電路實現上比最佳式選擇性分集與最大比率合成來擁有較小之面積與較低之功率消耗。所提出之(α+|r|)選擇性合成在性能上與最佳式選擇性合成相似，但優於傳統上之訊雜比(signal to noiseratio, SNR)選擇性合成。
本論文亦將所新提出之(α +|r|)與文獻上現有之|r|與|αr|等三種不同之統計變數(statistics variable)作為多分隻切換停留合成(multibranch switch-and-stay combining, MSSC)與切換檢查合成(switch-and-examine combining, SEC)之切換依據並分析其在統計獨立之瑞利衰減通道上的性能。另外本論文亦提出一種結合選擇性合成與切換停留合成之新的合成技術。該技術用於雙分支之情況下，此技術為選擇切換合成(selection and stay combining, SSTC)。本論文針對選擇切換合成在統計獨立與相關之中山(Nakagami)衰落通道進行分析。

關鍵字

選擇性合成 ； 切換式合成 ； 瑞利衰減通道 ； 中山衰落通道

並列摘要

In this thesis, three diversity schemes are proposed and analyzed. First, a new selection combining (SC) scheme is proposed. Compared to the optimal SC and maximal ratio combining (MRC), the new proposed SC scheme only uses adders for diversity combining and is much more power-saving and faster. The performance of the proposed SC scheme is similar to that of the optimal SC and considerably outperforms the traditional signal-to-noise-ratio (SNR) based SC. Second, three multibranch switch-and-stay combining (MSSC) diversity schemes with different statistics of switch decision are analyzed for independent Rayleigh fading channels. Third, by combining the SC and SSC, another new dual-branch selection-and-stay combining (SSTC) is considered and analyzed for diversity reception on independent and correlated Nakagami-m fading channels, where the conventional SC is employed only at the switching instance, and the receiver uses the selected branch till its SNR is lower than a preset threshold.
For all proposed SC- and/or SWC-based diversity combining schemes, theoretical performance evaluations are given, and numerical results from analysis and Monte-Carlo simulation are presented.

並列關鍵字

selection diversity ； switch diversity ； Rayleig fading channels ； Nakagami-m fading channels

參考文獻

[1] D. G. Brennan, “Linear diversity combining techniques,” Proc. IRE, vol. 47, pp.1075-1102, June 1959.

[2] M. K. Simon and M. S. Alouini, Digital Communication over Fading Channels, John Wiley & Sons, Inc., 2005.

[3] M. A. Blanco and K. J. Zdunek, “Performance and optimization of switched diversity systems for the detection of signals with Rayleigh fading,” IEEE Trans.

[4] Y. A. Chau and Y. -H. Chen, “Selection-and-stay combining on correlated Nakagami fading channel,” Electronics Letters, vol. 45, pp. 559-561, May 2009.

[5] E. Neasmith and N. Beaulieu, “New results on selection diversity,” IEEE Trans. Commun., vol. 46, pp. 695-704, May 1998.