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DESIGN AND ANALYSIS OF HIGH-PERFORMANCE
COOPERATIVE RELAY NETWORKS
by
Wan-Jen Huang
A Dissertation Presented to the
FACULTY OF THE GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
DOCTOR OF PHILOSOPHY
(ELECTRICAL ENGINEERING)
May 2008
Copyright 2008 Wan-Jen Huang
Object Description
| Title | Design and analysis of high-performance cooperative relay networks |
| Author | Huang, Wan-Jen |
| Author email | wanjenhu@usc.edu |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Electrical Engineering (Multimedia & Creative Technology) |
| School | Viterbi School of Engineering |
| Date defended/completed | 2008-01-23 |
| Date submitted | 2008 |
| Restricted until | Unrestricted |
| Date published | 2008-04-18 |
| Advisor (committee chair) | Kuo, C.-C. Jay |
| Advisor (committee member) |
Sun, Fengzhu Chugg, Keith |
| Abstract | Cooperative communications have aroused considerable attention in recent years since it exploits the spatial diversity gains inherent in multi-user wireless systems without the need of multiple antennas at each node. In this dissertation, we consider to enhance the performance of energy-constrained ooperative networks in two aspects.; First, we devise power allocation strategies to maximize the lifetime of the amplify-and-forward (AF) cooperative network. Based on selective relaying, we propose three strategies that take into account the local channel state information (CSI) and the local residual energy information (REI) at each relay to prolong the network lifetime. With a finite number of power levels, the energy dissipation process can be modeled as a finite-state Markov chain and the optimal lifetime maximization strategy can be derived using dynamic programming. We demonstrate that the network lifetime can be extended considerably by exploiting both CSI and REI via numerical simulation. The performance of the proposed strategies that utilize only local CSI and REI is shown to be comparable to that of the optimal strategy that demands global CSI and REI.; Second, we examine the uplink of a synchronous cooperative CDMA network, where users cooperate by relaying each other's messages to the base station. When spreading waveforms are not orthogonal, multiple access interference (MAI) exists at relays and the destination, causing the cooperative diversity gain to diminish. To address this problem, we propose the relay-assisted decorrelating multiuser detector (RAD-MUD) to separate interfering signals at the destination with the help of precoding at relays along with pre-whitening at the destination. Three cooperative transmission strategies are considered on top of RAD-MUD; namely, transmit beamforming, selective relaying and distributed space-time coding. Since the reliability of each source-relay and/or relay-destination links is different, relay transmissions are weighted accordingly to further combat MAI. The RAD-MUD system is extended to cooperative networks, where asynchronism of transmissions among the source nodes and relay nodes is taken into consideration. Theadvantages of RAD-MUD over existing cooperative MUD schemes are verified by computer simulation. |
| Keyword | coopertive networks; power allocation; lifetime maximization; multiuser detection |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Type | texts |
| Legacy record ID | usctheses-m1141 |
| Rights | Huang, Wan-Jen |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | http://www.usc.edu/isd/libraries/services/ask_a_librarian/email/ |
| Filename | etd-Huang-20080418 |
| Archival file | uscthesesreloadpub_Volume14/etd-Huang-20080418.pdf |
Description
| Title | Page 1 |
| Full text | DESIGN AND ANALYSIS OF HIGH-PERFORMANCE COOPERATIVE RELAY NETWORKS by Wan-Jen Huang A Dissertation Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (ELECTRICAL ENGINEERING) May 2008 Copyright 2008 Wan-Jen Huang |
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