ABSTRACT: Efficient radio resource management is a key requirement in emerging and future broadband wireless networks. In this seminar we focus on presenting our research into radio resource management for two types of networks: multi-cell LTE networks and cognitive radio networks. For LTE networks we describe a novel resource allocation scheme to achieve a balanced performance improvement for all users subject to inter-cell interference. In the scheme the resource allocation process is implemented in two steps. In the first step interference coordination and scheduling are conducted in a global manner to prevent cell-edge users from mutual interference. This includes two different approaches: a greedy-based resource allocation algorithm and a soft frequency reuse (SFR) approach to deal with major inter-cell interference between cell-edge and cell-center users. In the second step, optimal power allocation is conducted to maximize performance of cell-edge users while maintaining high performance of cell-center users. The optimal power allocation problem is solved using the Lagrange decomposition method. Simulation results show that the scheme can significantly improve performance for all users in a multi-cell network and achieve a good performance balance between cell-edge and cell-center users. For cognitive radio networks we describe a novel dynamic spectrum sensing and access model that allows secondary users to sequentially sense two channels in a single time slot and provides coordinated access of multiple secondary users to the available channels. The access model is formulated as a channel assignment optimization problem which is shown to be NP-hard. We analyze a Markov chain based greedy channel assignment scheme which allows for sequential sensing of two channels with a priority order per time slot and evaluate the performance of this approach in a saturated network. The analytical results indicate that the approach can achieve significant improvements in terms of secondary user throughput and MAC delay. In this seminar we also present an overview of an experimental cognitive radio network testbed aimed at testing and validating radio resource mamanegemnt algorithms in laboratory settings.

 

SPEAKER: Professor Eryk Dutkiewicz (http://web.science.mq.edu.au/directory/listing/person.htm?id=eryk) has over 25 years of industrial and academic research experience. He obtained his Bachelor of Electrical and Electronic Engineering from the University of Adelaide, Australia in 1988, his Master of Science in Applied Mathematics from the University of Adelaide, Australia in 1992 and his PhD (Telecommunications) from the University of Wollongong, Australia in 1996. He has conducted research and development with network operators and equipment manufacturing companies. He began his research career at OTC R&D Laboratories in Sydney in 1988 working on pioneering broadband networking technologies. From 1999 to 2004 he worked at Motorola Laboratories in Sydney where he managed a wireless research laboratory. During that time he was also deeply involved in the development of various wireless standards, including those for the popular WiFi technology. Since returning to academia in 2004 he has worked closely with industry partners including Motorola, Agere Systems, Freescale Semiconductor, Infineon Technologies, Intel, Zarlink and CSIRO on projects involving wireless sensor networks, mesh networks, ultra-wideband technologies, 4G mobile communications networks and medical wireless body area networks. He joined Macquarie University in 2008 as a Professor of Wireless Communications and established the Wireless Communications and Networking Laboratory (http://web.science.mq.edu.au/groups/wireless/). The focus of the Laboratory is on developing wireless technologies for novel medical applications and future generation of mobile communications systems. Prof. Dutkiewicz keeps close research collaboration links with several premier institutions around the world including the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia and the Chinese Academy of Sciences in Beijing. He has held visiting professorial appointments at the Chinese Academy of Sciences, Shanghai Jiao Tong University and City University of Hong Kong. Prof. Dutkiewicz has also close links with the local industry and he is the academic co-ordinator for the Engineering Industry Partnership Program at Macquarie University. He is an author of over 150 research papers and several book chapters. His professional activities in recent years have included participation and development of IEEE standards in the USA - IEEE 802.11, 802.15.4, 802.15.6, General Chair of 7th and 12th International Symposium on Communications and Information Technologies (ISCIT 2007 and ISCIT2012), Editorial Board Member of PHYCOM Physical Communication Journal (Elsevier), member of various International Steering Committees including IEEE TENCON 2008 and 2012 and TPC member on numerous IEEE conferences.