Analysis of Spectrum Efficiency and Energy Efficiency of Heterogeneous Cellular Networks

The rise in the plethora of handheld devices, fuelled by increasing demand for personalized wireless user experience has led to the wide-scale deployment of heterogeneous cellular networks (HetNets) comprising large-scale macrocell base stations (BSs) overlaid with multiple tiers of small cell BSs. While the HetNets are capable of increasing the spectrum efficiency (SE) through higher reuse of the available spectrum, the operation of the BSs comes at a huge increase in the overall network power expenditure, leading to the deterioration of the energy efficiency (EE) performance. For sustainable operation of cellular networks, maintaining both performance metrics (SE and EE) at the highest possible level is of fundamental importance, hence, gaining an in-depth understanding into the interrelationship between the SE and EE is imperative. This thesis develops a tractable analytical framework for investigating the SE and EE of multi-tier cellular networks, based on which a number of network resource management techniques are proposed for achieving a good balance in the SE-EE tradeoff. First, to realistically model the HetNet BS deployment, mathematical tools from Stochastic Geometry are utilized, following which the SE and EE are analytically characterized when operating under a shared spectrum scenario. Second, the ability to increase the power savings at the BSs while satisfying the users’ Quality of Service requirements is investigated, considering the downlink fractional power control and fractional frequency reuse techniques. Third, to support a higher number of users and to utilize the additional spectrum in different radio access technologies, the inter-operability between the cellular and wireless local area network is considered. Based on this, the feasibility of increasing the SE and EE via the implementation of biased intra- and inter-radio access technologies (RAT) offloading techniques is investigated. Several multi-objective optimization problems that jointly maximize the SE and EE are formulated and solved to give the Pareto optimal operational regimes, specified in terms of the network parameters. Overall, the work done in this thesis provides key insights into the SE and EE interrelationship, instrumental for the development of more advanced network resource management techniques for sustainable future cellular networks.

Name thesis:degree_name

Doctor of Philosophy (PhD)

Discipline thesis:degree_discipline

Electrical and Computer Engineering

Grantor dc:publisher.institution

Graduate Studies

Year dc:date.issued

2014

Author dc:creator

• Buloo Karavu, Jaya Bharatha Rao

Advisor dc:contributor.advisor

• Fapojuwo, Abraham

• Engineering--Electronics and Electrical

Statement dc:rights

• University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.

Language dc:language.iso

eng

DOI

http://dx.doi.org/10.11575/PRISM/24823

OAI identifier oai:identifier

oai:ucalgary.scholaris.ca:11023/1670