Distributed Relays in Wireless Communication Networks

• Other Authors: Ding, Tian (author.)
• Format: Others
• Language: English; Chinese
• Published: 2016
• Online Access: http://repository.lib.cuhk.edu.hk/en/item/cuhk-1292305

本論⽂探討了分佈中繼無線網絡的性能極限。該系統中，兩個或多個⽤⼾，在多個中繼節點的幫助下進⾏通信。由於中繼節點在地理上是分隔的，不同中繼節點無法通過共享接收信號來進⾏合作通信。在本論⽂中我們重點討論兩種分佈中繼模型：雙路中繼通道與雙中繼多輸⼊多輸出Y 通道。 === 本論⽂第⼀部分研究了有源節點與⽬標節點間直通鏈路的雙路中繼通道的平均可達傳輸速率。我們提出了⼀種使⽤ Nested Lattic 編碼的譯碼前傳⽅案。該⽅案不僅可以完全消除中繼間噪聲，還可以在接收節點上有效地結合來⾃中繼和直接連路的信號進⾏連續譯碼。我們推導了該⽅案的平均可達傳輸速率，從可達傳輸速率來看，新⽅案顯著優於現有⽂獻中的⽅案。 === 本論⽂第⼆部分研究了雙中繼多輸⼊多數出Y通道的可達⾃由度。該系統中三個各配置了M根天線的⽤⼾節點，在兩個各配置了N根天線的中繼節點的幫助下，相互交換信息。在線性預編碼和線性接收處理的假設下，我們以公式構建了該模型的⾃由度可達性問題。為了解決該問題，我們提出了⼀種基於上下⾏不對稱的設計思路：以信號對⿑為⽬的設計⽤⼾的預編碼器，并以⼲擾消除為⽬的設計⽤⼾的接收處理器。基於該設計⽅案，我們在任意的天線配置下推導了該模型的可達⾃由度，并證明了該可達⾃由度在某些天線配置下的最優性。另外，分析表明該設計⽅案顯著優於傳統的基於上下⾏對稱的設計⽅案。 === In this thesis, we study the fundamental limits of the wireless communication networks with distributed relays, where two or more user nodes communicate with the help of multiple relay nodes. Since the relay nodes are geographically separated, they cannot cooperate with each other by sharing the received signals. We focus on two distributed relaying models: two-path relay channel and two-relay multiple-input multiple-output(MIMO) Y channel. === The first part of this thesis studies the average achievable rate of twopath relay channel with direct link between source and destination. We present a decode-and-forward cooperative transmission scheme based on nested lattice codes. Our scheme performs complete inter-relay interference(IRI) cancellation at the relays as well as successive decoding at the destination, which efficiently combines the signals from the source and the relays. We derive the achievable rates of our scheme, and show that our scheme considerably outperforms the existing schemes in the literature. === The second part of this thesis studies the achievable degrees of freedom(DoF) of two-relay MIMO Y channel, where three users, each equipped with M antennas, exchange messages via multiple geographically separated relay nodes, each with N antennas. We formulate a general DoF achievability problem assuming the use of linear precoding and postprocessing. To solve this problem, we present a new uplink-downlink asymmetric strategy where the user precoders are designed for signal alignment and the user post-processors are used for interference neutralization. Based on that, we derive an achievable DoF of the considered model for an arbitrary antenna setup. The optimality of the derived DoF is established under certain antenna configurations. Also, we show that our design considerably outperforms the conventional uplink-downlink symmetric design. === Ding, Tian. === Thesis M.Phil. Chinese University of Hong Kong 2016. === Includes bibliographical references (leaves ). === Abstracts also in Chinese. === Title from PDF title page (viewed on …). === Detailed summary in vernacular field only. === Detailed summary in vernacular field only. === Detailed summary in vernacular field only.