相關性通道缺陷狀態下運用放大轉發式MIMO中繼節點選擇之強健型預編碼器設計

Robust Joint Transceiver/Relays Design for AF-MIMO Relaying Selection with Correlated Channel Uncertainties

林聖翔(Lin Sheng Shang)

指導教授 ： 胡家彰

國立中正大學/工學院/通訊工程學系/碩士(2012年)

摘要

傳送端預編碼技術能根據通道狀態資訊(channel state information, CSI)調整傳送訊號藉以提高訊號品質，結合無線中繼網路(relay networks)則可增進系統效益。但在多中繼節點的情況下，並未考慮中繼節點的通道狀態，導致傳輸功率的浪費。因此本論文除了放大轉發式(amplify-and-forward, AF) 多重輸入多重輸出(multiple-input multiple-output, MIMO)之多中繼節點(multiple relays)通訊系統之聯合收發機設計，更進一步考慮最佳中繼節點的選擇。統合來源節點預編碼器(precoder)與中繼節點加權(weighting)矩陣以及目的節點解碼器(decoder)之設計將其制定成無限制條件下之最佳化的問題，在選擇最佳中繼點及處理解碼矩陣則使用最小均方誤差(minimum mean-square error, MMSE)準則，接著使用非線性矩陣型式共軛梯度法(matrix conjugate gradient method, MCG)搜尋區域最佳預編碼器以及各中繼加權矩陣。並將通道狀態資訊不完整以及傳送/接收兩端天線陣列皆具有相關性情況下考慮於設計問題之中發展出強健型聯合收發機設計。最後，電腦模擬結果方面，則與其他不同的聯合收發機設計和中繼節點選擇方式做比較，證明本文所提出的聯合收發機設計暨中繼節點選擇法兼具低複雜度及提高系統效益。

關鍵字

放大轉發式 ； 通道狀態資訊不完整 ； 多輸入多輸出 ； 最小均方誤差 ； 中繼節點選擇 ； 預編碼器

並列摘要

Multiple-input multiple-output (MIMO) communication systems with multiple relays are able to improve system efficiency and transmission reliability. However, the transmission power might be wasted because some relays with bad channel state information (CSI) are incorporated. The use of relay selection is one of the most effective ways to conquer this problem. In the thesis, a robust transceiver joint optimization is proposed by taking the concepts of relay selection and correlated channel uncertainties into consideration. This architecture of relay selection and transceiver joint optimization is developed based on the minimum mean-squared error (MMSE) criterion under individual power constraints at the source and relays. An iterative nonlinear matrix conjugate gradient (MCG) method is applied to exploit source/relays precoder matrices. Simulation results show that the robust relays/transceiver joint design architecture for an AF-MIMO multiple-relay system with the use of relay selection is less complex and better performance than other existing robust joint transceiver designs with relay selection.

並列關鍵字

Amplify-and-forward (AF) ； channel uncertainty ； MIMO ； MMSE ； multiple relays ； precoder ； relay selection

參考文獻

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