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Resource allocation and performance evaluation in heterogeneous and relay-based wireless networks

University of British Columbia

In the last decade, mobile data demand has been exponentially growing. Telecommunication industry finds it increasingly difficult to cope with this exponential growth through conventional cellular networks with carefully planned high power macro base stations (BSs). Therefore, the densification of BSs through introduction of low power BSs has been considered for implementation. The combination of macro BSs and low power BSs such as pico and femto BSs as well as relay nodes is referred to as heterogeneous networks (HetNets). HetNets impose major technical challenges in implementation such as severe interference cases and imbalance of load among macro BSs and low power BSs. One problem that needs to be re-addressed in the context of HetNets is the cell association problem. Although centralized cell association schemes are important in realizing the potentials of HetNets, mobile operators are interested in distributed schemes in which network elements decide based on their local information. In this thesis, we consider distributed cell association algorithms with quality of service provisioning. First, we propose a unified cell association algorithm that is particularly designed for downlink. Next, we consider uplink to have a downlink and uplink aware cell association scheme. The performances of the proposed schemes are examined through numerical simulations. Cooperative relay-based communication combined with orthogonal frequency division multiplexing (OFDM) and its multi access variant, orthogonal frequency division multiple access (OFDMA) has gained an immense interest in the last decade. Among all the research topics in OFDM relay-based communication, analyzing the outage behavior has been an invariable concern to researchers. To analyze the outage behavior, most of the researchers ignore the correlation between OFDM subchannels, and also assume equal bit allocation on all the subchannels. In this thesis, we analyze the outage behavior of a three-node OFDM relay-based network when these two assumptions are relaxed. Next, we characterize the global outage probability of a multi-user single-relay OFDMA network. Finally, a network consisting of a cluster of source-destination pairs and a cluster of relays is considered where we propose a low complexity relay allocation scheme. The outage analyses and the relay allocation scheme are examined through numerical simulations.

Text

2014-08-26

Attribution-NonCommercial-NoDerivs 2.5 Canada

http://hdl.handle.net/2429/50207

Electrical and Computer Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/2.5/ca/