近年來，無線通訊以飛快的速度發展著，行動網路也已經步入第四代行動通訊的傳輸架構，人們持有的使用者裝置將獲得更高的服務品質以及更快的傳輸速率。在第四代合作夥伴計畫當中，增加多點協調傳輸系統(Coordinated Multi-Point System, CoMP)來增強長期演進(Long Term Evolution-Advanced, LTE-A)技術，透過協調蜂巢中每一個演進結點，調整傳送的波束賦形(beamforming)向量達到降低同頻干擾並提升蜂巢邊緣(cell edge)使用者裝置的傳輸呑吐量(throughput)。下行多點協調傳輸系統，主要分為聯合處理(Joint Processing, JP)及波束賦形協調(Coordinated Beamforming, CB)。另一方面，隨著半導體的發展，使用者裝置具備更多的功能，且擁有更高畫素及尺寸更大的螢幕，這些發展意味著使用者裝置更加耗電。但電池並沒有其他電子裝置發展得快，因此有學者提出將接收之電磁波轉為能量儲存，已延長電子裝置的使用時間，此技術稱為無線能量傳輸(Wireless Energy Transfer, WET)。在本論文中，我們使用者需要接收資訊及汲取能量的多點協調系統，在此架構下，設計多點協調傳輸系統的波束賊形向量將是我們討論的重點。基於實現複雜度的考量，我們提出下行CoMP-CB系統中使用者裝置存著能量採集(Energy Harvesting, EH)及資訊解碼(Information Detection, ID)兩種功能且兩種功能分時進行，也就是說，傳輸系統中部份使用者裝置接收能量，部份使用者裝置接收資訊。藉由最佳化波束賊形向量及選擇使用者的運作模式，我們需要保障工作於資訊解碼使用者裝置的傳輸速率總和須達到標準，讓工作於能量採集使用者裝置採集的能量達到最大化。除此之外，我們也將考慮部分通道資訊的情況進行預編碼設計，以克服通道資訊無法完美取得的情形。

In recent years, wireless communication has been developed quickly, and the mobile network has proceeded to the fourth generation communication systems. The subscriber’s handheld devices are going to have higher quality services and faster transmission throughput. In the fourth generation partnership project, coordinated multi-point (CoMP) transmission technique has been proposed to enhance the signal quality of the Long-Term Evolution-Advanced (LTE-A) systems. Through coordination among multiple cells, e-NodeBs (eNBs) adjust corresponding transmit beamforming vectors in order to reduce co-channel interference as well as improve transmission throughput of users located at cell edge. Downlink coordinated multi-point transmission techniques can be classified into the joint processing (CoMP-JP) and coordinated beamforming (CoMP-CB). On the other hand, as the development of semiconductor, mobile devices become more powerful and are usually equipped with high quality panel, which consumes battery power faster. However, progress on the battery is not as faster as electronic devices. Thus, the technique of wireless energy transfer (WET) has been proposed to harvest energy and provides longer lifetime for the user’s devices. In the thesis, we consider a CoMP system where users need to receive information and harvest energy simultaneously. We focus on the design of beamforming vector to meet the requirement of energy harvesting and information detection. Taking implementation complexity into consideration, we propose a downlink CoMP-CB scheme where each user can operate under either energy-harvesting mode or energy-detection mode. By optimizing the beamforming vectors and selecting operation modes for users, the proposed scheme aims to maximize the harvested energy, subject to guaranteeing sum-rate constraints for those users in information-detection mode. Finally, we also consider the case of partial CSI, and design the beamforming scheme accordingly, in order to deal with the situation that perfect CSI is not available.

論文審定書i
致謝 ii
摘要 iii
Abstract iv
目錄 vi
圖次 vii
第一章 簡介 1
第二章 文獻探討 5
2.1.1能量採集及資訊解碼同時運作的下鏈網路 5
2.1.2能量採集及資訊解碼分時運作的多天線傳輸系統 7
2.2.1 CoMP-CB 系統 9
第三章 系統模型 12
第四章 預編碼設計 16
4.1完整通道資訊下的預編碼向量 17
4.2通道估測存在誤差的預編碼設計 20
4.3 利用通道統計特性設計預編碼器 25
第五章 模擬解果 29
第六章 結論 36
參考文獻 37
附錄 39

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