Relay Selection and Max-Min Resource Allocation in OFDM-Based Cooperative Networks

Relay Selection and Max-Min Resource Allocation in OFDM-Based Cooperative Networks Kianoush Hosseini Master of Applied Science Graduate Department of Electrical and Computer Engineering University of Toronto 2010 This thesis considers resource allocation to achieve the max-min fairness in a selectionbased OFDM network wherein source nodes are assisted by fixed relays. Transmission strategy selection, relay assignment, and power allocation at the sources and relays are considered crucial in architecture design of such networks. However, this is a combinatorial problem with exponential complexity. In this thesis, we investigate two relaying scenarios, i.e., subcarrier-based and blockbased relaying. In subcarrier-based relaying, all subcarriers are assumed to be independent transmissions while relays use decode-and-forward protocol. However, in addition to the synchronization problems caused, it is likely impractical for a relay to only decode a subset of subcarriers. This motivates a search for practical block-based schemes. We also propose a simple, decentralized, block-based relaying scheme. Simulation results using the COST-231 channel model reveals that this scheme has a close-to-optimal performance while offering computational benefits.