Optimisation and algorithms in wireless networks for mission critical applications

The focus of this dissertation is to present novel algorithms and techniques in wireless network systems aiming at performance optimisation. This thesis provides contribution to knowledge on the following topics: (a) sum rate maximisation of two interfering users in an Orthogonal Frequency Division Multiple Access (OFDMA)-based cooperative base stations and (b) event-region detection in Wireless Sensor Networks (WSNs). The first area of work makes contribution on problem of maximising the sum rate of two interfering users, while limiting the received interference at each user. An OFDMA-based system operating in downlink is considered. Comparisons between achieved average spectral efficiency of proposed interference power constraint resource allocation scheme as opposed to achieved average spectral efficiency by non-cooperative Time Division Multiple Access (TDMA) method is provided to prove that the proposed cooperative Base Stations (BSs) scheme outperforms non-cooperative TDMA. The second area of work makes contribution on problem of event region and event boundary detection in WSNs. A new method for classifying randomly deployed sensor nodes over an area of interest into distinctive categories is provided. In this work, a network of spatially distributed and wirelessly connected sensor nodes commissioned to detect two different phenomena, occurring in distant parts of an area of interest, is considered. Analysis on correlation between statistical attributes of received signal distribution at each node and the node’s regional position with respect to two events is provided. Simulation results proves that each node can acknowledge its regional position based only on the statistical attributes of its own environmental readings. This is a promising approach because if only the nodes placed in the close by region of each phenomena report back their reading to the Base Station (BS), as opposed to transmitting entire readings from all nodes, the required bandwidth reduces to be proportional to the size of that event-region only.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

University of Greenwich

Year dc:date.issued

2015

Author dc:creator

• Tavakoli Dehkordi, Anousheh

Advisors dc:contributor.advisor

• Rapajic, Predrag
• Wu, Ruiheng

• QC Physics
• TJ Mechanical engineering and machinery

Language dc:language

en