當前的行動全球微波存取互通介面(mobile WiMAX)能保證在廣域網路上達成行動通訊裝置的低消耗目標。更詳細的說，mobile WiMAX結合了多重輸入多重輸出(MIMO)與中繼傳輸(relay transmission)等技術以達到易適性頻寬與快速連結。在這篇論文裡，我們提出加權濾波器(weighting filter)與策略性的架設中繼基地台(relay station)以同步增進通道容量(channel capacity)與能量效率(power-efficient)。更確切的說，我們首先探討了行動通訊裝置藉由中繼基地台傳輸至基地台(base station)的通道容量在現有的兩種中繼傳輸系統上：analogue(amplify and forward) relaying 與 digital(decode and forward) relaying。而為了增強通道容量，我們根據通道狀態(channel state information)提出了兩種有效的加權濾波器(Matched filter與Minimum Mean Square Error(MMSE) filter)被採納在中繼基地台上。另外，我們亦提出了一種新穎的策略性架設中繼基地台的能量節省(power-saving)方法，並用分支定界演算法(Branch-and-Bound(BB) algorithm)來解決問題。結果顯示在中繼基地台上採納matched filter能夠顯著地增進通道容量；策略性的架設中繼基地台亦能達到明顯的能量節省增益。最後，我們也確認了分支定界演算法能有效的降低計算複雜度。

The latest mobile WiMAX standard promises to enable low-cost mobile Internet applications over extensive areas and
to meet the capacity requirements. More specifically, mobile WiMAX combines advanced MIMO schemes and relay transmission technique along with flexible bandwidth and fast link adaptation. In this paper, we propose the weighting filter to increase capacity and conserve power-consumption by deployment strategy simultaneously in anticipation of growing customer demands. Indeed, the channel capacity for two well known relaying schemes are investigated: analogue (amplify and forward) relaying and digital (decode and forward) relaying from a mobile device to the base station through a relay node. In order to further increase the channel capacity, we propose two efficient weight functions (Matched filter and Minimum Mean Square Error (MMSE) filter) adopted by relay node according to the wireless channel condition. In addition, a new power saving scheme by introducing the problem for relay stations (RSs) deployment and adopt the Branch-and-Bound (BB) algorithm to solve this problem is also presented. Furthermore, our numerical results demonstrate the significant improvement of network capacity by applying the matched filter weight at relay nodes and verify the effectiveness for the proposed BB algorithm. Finally, the significant performance gain can be achieved when RSs are strategically installed in the network.

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