Coherent receiver design and analysis for interleaved division multiple access (IDMA)

This thesis discusses a new multiuser detection technique for cellular wireless communications. Multiuser communications is critical in cellular systems as multiple terminals (users) transmit to base stations (or wireless infrastructure). Efficient receiver methods are needed to maximise the performance of these links and maximise overall throughput and coverage while minimising inter-cell interference. Recently a new technique, Interleave-Division Multiple Access (IDMA), was developed as a variant of direct-sequence code division multiple access (DS-CDMA). In this new scheme users are separated by user specific interleavers, and each user is allocated a low rate code. As a result, the bandwidth expansion is devoted to the low rate code and not weaker spreading codes. IDMA has shown to have significant performance gains over traditional DS-CDMA with a modest increase in complexity. The literature on IDMA primarily focuses on the design of low rate forward error correcting (FEC) codes, as well as channel estimation. However, the practical aspects of an IDMA receiver such as timing acquisition, tracking, block asynchronous detection, and cellular analysis are rarely studied. The objective of this thesis is to design and analyse practical synchronisation, detection and power optimisation techniques for IDMA systems. It also, for the first time, provides a novel analysis and design of a multi-cell system employing a general multiuser receiver. These tools can be used to optimise and evaluate the performance of an IDMA communication system. The techniques presented in this work can be easily employed for DS-CDMA or other multiuser receiver designs with slight modification. Acquisition and synchronisation are essential processes that a base-station is required to perform before user's data can be detected and decoded. For high capacity IDMA systems, which can be heavily loaded and operate close to the channel capacity, the performance of acquisition and tracking can be severely affected by multiple access interference as well as severe drift. This thesis develops acquisition and synchronisation algorithms which can cope with heavy multiple access interference as well as high levels of drift. Once the timing points have been estimated for an IDMA receiver the detection and decoding process can proceed. An important issue with uplink systems is the alignment of frame boundaries for efficient detection. This thesis demonstrates how a fully asynchronous system can be modelled for detection. This thesis presents a model for the frame asynchronous IDMA system, and then develops a maximum likelihood receiver for the proposed system. This thesis develops tools to analyse and optimise IDMA receivers. The tools developed are general enough to be applied to other multiuser receiver techniques. The conventional EXIT chart analysis of unequal power allocated multiuser systems use an averaged EXIT chart analysis for all users to reduce the complexity of the task. This thesis presents a multidimensional analysis for power allocated IDMA, and shows how it can be utilised in power optimisation. Finally, this work develops a novel power zoning technique for multicell multiuser receivers using the optimised power levels, and illustrates a particular example where there is a 50% capacity improvement using the proposed scheme. -- provided by Candidate

Cognitive Radio Systems

Cognitive radio is a hot research area for future wireless communications in the recent years. In order to increase the spectrum utilization, cognitive radio makes it possible for unlicensed users to access the spectrum unoccupied by licensed users. Cognitive radio let the equipments more intelligent to communicate with each other in a spectrum-aware manner and provide a new approach for the co-existence of multiple wireless systems. The goal of this book is to provide highlights of the current research topics in the field of cognitive radio systems. The book consists of 17 chapters, addressing various problems in cognitive radio systems

Distributed power control in ad hoc networks.

Thesis (M.Sc.Eng.)-University of Natal, Durban, 2003.Abstract available in digital copy

Resource allocation for wireless networks: learning, competition and coordination.

Lin, Xingqin.Thesis (M.Phil.)--Chinese University of Hong Kong, 2011.Includes bibliographical references (p. 103-109).Abstracts in English and Chinese.Abstract --- p.iAcknowledgement --- p.iiiChapter 1 --- Introduction --- p.1Chapter 1.1 --- Motivation --- p.1Chapter 1.2 --- Background --- p.3Chapter 1.2.1 --- Wireless Communication Schemes --- p.3Chapter 1.2.2 --- Mathematical Preliminaries --- p.8Chapter 1.3 --- Outline of the Thesis --- p.12Chapter 2 --- Learning for Parallel Gaussian Interference Channels --- p.14Chapter 2.1 --- System Model and Problem Formulation --- p.16Chapter 2.2 --- Stochastic Algorithm for Learning --- p.18Chapter 2.2.1 --- Algorithm Design --- p.18Chapter 2.2.2 --- Convergence Analysis --- p.21Chapter 2.3 --- Continuous Time Approximation --- p.26Chapter 2.4 --- Learning with Averaging --- p.28Chapter 2.5 --- Numerical Results --- p.29Chapter 3 --- Power Control for One-to-Many Transmissions --- p.34Chapter 3.1 --- System Model --- p.35Chapter 3.2 --- A GNEP Approach --- p.38Chapter 3.2.1 --- Problem Formulation --- p.38Chapter 3.2.2 --- Preliminary Results --- p.39Chapter 3.3 --- Algorithm Design --- p.42Chapter 3.4 --- Numerical Results --- p.46Chapter 4 --- Flow Allocation in Multiple Access Networks --- p.50Chapter 4.1 --- System Model and Problem Formulation --- p.52Chapter 4.1.1 --- System Model --- p.52Chapter 4.1.2 --- Problem Formulation --- p.53Chapter 4.2 --- Characterization of NE --- p.57Chapter 4.2.1 --- Feasibility Assumption --- p.57Chapter 4.2.2 --- Existence and Uniqueness of NE --- p.58Chapter 4.3 --- Distributed Algorithms Design --- p.60Chapter 4.3.1 --- D-SBRA --- p.60Chapter 4.3.2 --- P-SBRA --- p.61Chapter 4.3.3 --- Best Response and Layered Structure --- p.65Chapter 4.4 --- Performance Evaluation --- p.67Chapter 4.4.1 --- Protocol Evaluation --- p.67Chapter 4.4.2 --- Convergence and Performance --- p.69Chapter 4.4.3 --- Flow Distribution --- p.71Chapter 4.4.4 --- A Grid Network Simulation --- p.73Chapter 5 --- Relay Assignment in Cooperative Networks --- p.76Chapter 5.1 --- System Model and Problem Formulation --- p.77Chapter 5.1.1 --- Three-Node Relay Model --- p.77Chapter 5.1.2 --- Network Model --- p.78Chapter 5.1.3 --- Problem Formulation --- p.78Chapter 5.2 --- Centralized Scheme --- p.80Chapter 5.2.1 --- Generalized Relay Assignment --- p.80Chapter 5.2.2 --- Admission Control --- p.83Chapter 5.2.3 --- Iteration Algorithm and Some Remarks --- p.84Chapter 5.3 --- A Simple Distributed Algorithm --- p.84Chapter 5.4 --- Numerical Results --- p.86Chapter 6 --- Conclusions and Future Work --- p.88Chapter 6.1 --- Conclusions --- p.88Chapter 6.2 --- Future Work --- p.89Chapter A --- Proof of Theorem 21 --- p.93Chapter B --- Proof of Theorem 22 --- p.96Chapter C --- Proof of Proposition 31 --- p.98Chapter D --- Proof of Proposition 44 --- p.101Bibliography --- p.10

Proceedings of the Second International Mobile Satellite Conference (IMSC 1990)

Presented here are the proceedings of the Second International Mobile Satellite Conference (IMSC), held June 17-20, 1990 in Ottawa, Canada. Topics covered include future mobile satellite communications concepts, aeronautical applications, modulation and coding, propagation and experimental systems, mobile terminal equipment, network architecture and control, regulatory and policy considerations, vehicle antennas, and speech compression

Proceedings of the Third International Mobile Satellite Conference (IMSC 1993)

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial cellular communications services. While the first and second International Mobile Satellite Conferences (IMSC) mostly concentrated on technical advances, this Third IMSC also focuses on the increasing worldwide commercial activities in Mobile Satellite Services. Because of the large service areas provided by such systems, it is important to consider political and regulatory issues in addition to technical and user requirements issues. Topics covered include: the direct broadcast of audio programming from satellites; spacecraft technology; regulatory and policy considerations; advanced system concepts and analysis; propagation; and user requirements and applications

SMARAD - Centre of Excellence in Smart Radios and Wireless Research - Activity Report 2011 - 2013

Centre of Excellence in Smart Radios and Wireless Research (SMARAD), originally established with the name Smart and Novel Radios Research Unit, is aiming at world-class research and education in Future radio and antenna systems, Cognitive radio, Millimetre wave and THz techniques, Sensors, and Materials and energy, using its expertise in RF, microwave and millimeter wave engineering, in integrated circuit design for multi-standard radios as well as in wireless communications. SMARAD has the Centre of Excellence in Research status from the Academy of Finland since 2002 (2002-2007 and 2008-2013). Currently SMARAD consists of five research groups from three departments, namely the Department of Radio Science and Engineering, Department of Micro and Nanosciences, and Department of Signal Processing and Acoustics, all within the Aalto University School of Electrical Engineering. The total number of employees within the research unit is about 100 including 8 professors, about 30 senior scientists and about 40 graduate students and several undergraduate students working on their Master thesis. The relevance of SMARAD to the Finnish society is very high considering the high national income from exports of telecommunications and electronics products. The unit conducts basic research but at the same time maintains close co-operation with industry. Novel ideas are applied in design of new communication circuits and platforms, transmission techniques and antenna structures. SMARAD has a well-established network of co-operating partners in industry, research institutes and academia worldwide. It coordinates a few EU projects. The funding sources of SMARAD are diverse including the Academy of Finland, EU, ESA, Tekes, and Finnish and foreign telecommunications and semiconductor industry. As a by-product of this research SMARAD provides highest-level education and supervision to graduate students in the areas of radio engineering, circuit design and communications through Aalto University and Finnish graduate schools. During years 2011 – 2013, 18 doctor degrees were awarded to the students of SMARAD. In the same period, the SMARAD researchers published 197 refereed journal articles and 360 conference papers