As a subtopic in this thesis, we also investigate how to deal with uncertainty in the context of the traditional Straightforward Network Coding (SNC) scheme. With the proposed scheme, Soft Network Coding, only simple symbol-level network coding operation at the physical layer of the relay node can achieve even better performance than the traditional SNC scheme, which needs the complicated channel decoding and re-encoding operation. / Network coding is a promising upper layer technique first proposed in the context of wired networks. In this thesis, we investigate the application of network coding at the physical layer of wireless networks to take into account the unique properties of wireless networks. Specifically, we propose a new network coding scheme referred to as Physical layer Network Coding (PNC). PNC effects network-coding operation directly at the physical layer by proper interpretation of EM (Electromagnetic) signal received simultaneously from multiple sources. From the network point of view, this scheme can approach the min-cut throughput for both bi-direction and uni-direction linear relay networks; from the information theory point of view, this scheme can approach the capacity of two-way relay channel in the low and high SNR regions. When channel coding is considered, we could classify PNC into two classes, end-to-end coded PNC and link-by-link coded PNC. For end-to-end coded PNC, we further classify it into subclasses: PNC over infinite field (PNCI) and PNC over finite field (PNCF). For each subclass, we propose and analyze new PNC mapping schemes. For link-by-link coded PNC, we focus on the transformation from the received packet Y3 to the network coded form of unchannel-coded packet S1⊕S2, referred to as the Channel-decoding-Network-Coding process (CNC). Among three CNC designs, a matched CNC, CNC3, is of great interest due to its superior performance. Therefore, we design a new decoding algorithm at the relay node to make CNC3 feasible. Simulation result shows that the matched CNC with our new decoding algorithm outperforms the two straightforward CNC designs significantly in terms of BER without added complexity. Overall, this thesis lays down the fundamentals and foundation of PNC. And through theoretical analysis and implementation constructions, we provide insights on how good performance in wireless networks can be achieved with PNC. / Zhang, Shengli. / Adviser: Soung Chang Lieu. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3709. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 178-183). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_344290 |
| Date | January 2008 |
| Contributors | Zhang, Shengli, Chinese University of Hong Kong Graduate School. Division of Information Engineering. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, theses |
| Format | electronic resource, microform, microfiche, 1 online resource (xv, 183 leaves : ill.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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