Blind equalization of non-irreducible and non-column-reduced channels driven by constant modulus signals

We address the blind equalization of finite-impulse-response (FIR), multiple-input multiple-output (MIMO) channels excited by constant modulus (CM) signals. It is known that the algorithms based on the constant modulus (CM) criterion can equalize an FIR MIMO channel that is irreducible and column-reduced. We show in this paper that the CM property of signals can be exploited to construct a zero-forcing equalizer for a non-irreducible and non-column-reduced channel. We also give a lower bound for the order of the equalizer. Simulation examples demonstrate the proposed result.

Precoder design for multi-antenna systems with temporally and spatially correlated fading channels

This paper addresses the problem of the design of a precoder for multiple transmit antenna communication systems with spatially and temporally correlated fading channels. Using the theories of matrix differential calculus, the paper derives a precoder for unitary space-time codes that can exploit the spatio-temporal correlation in the time-varying fading channels. The design criterion is based on minimizing the mean square error of the channel estimates. Computer simulation results show that a significant performance gain can be achieved by using the designed precoder.

State and input simultaneous estimation for a class of nonlinear systems

This paper addresses the problem of estimating simultaneously the state and input of a class of nonlinear systems. Here, the systems nonlinear part comprises a Lipschitz nonlinear function with respect to the state and input, and a state-dependent unknown function including additive disturbance as well as uncertain/nonlinear/time-varying terms. Upon satisfying some conditions, the observer design problem can be solved via a Riccati inequality or a LMI-based technique with asymptotic estimation guaranteed. A numerical example is included for illustration.

State and input simultaneous estimation for a class of time-delay systems with uncertainties

This brief addresses the problem of estimation of both the states and the unknown inputs of a class of systems that are subject to a time-varying delay in their state variables, to an unknown input, and also to an additive uncertain, nonlinear disturbance. Conditions are derived for the solvability of the design matrices of a reduced-order observer for state and input estimation, and for the stability of its dynamics. To improve computational efficiency, a delay-dependent asymptotic stability condition is then developed using the linear matrix inequality formulation. A design procedure is proposed and illustrated by a numerical example.

How E-business can provide a sustainable framework for online learning in the vocational education and training arena

The author undertook a major national study of e-business for the Australian National Training Authority (ANTA) from November 1999 - February 2000, resulting in the report E-competent Australia: The Impact of E-commerce on the National Training Framework (ANTA, 2000; available at http;://www.anta.gov.au). This ANTA study and other research by the author show that e-business will eventually have a significant impact on the Australian economy, on industries, organisations, occupations and education and training organisations. From April-May 2000, the author is undertaking a major study for the Commonwealth Government (DETYA): a scoping study of e-commerce in the education and training sector (higher education, VET, schools) of Australia.

This paper starts where the ANTA study (Mitchell 2000a) and the DETYA study stop, by exploring the implications of e-business for online learning systems. E-business will eventually impact not only on the organisations providing online education but on their online learning systems.

The paper is based also on research by the author for a Doctorate in Education within the Faculty of Education at Deakin University that commenced in 1997 and is continuing. The research for this paper involved a review of national and international developments in ebusiness, relating them to online learning systems.

This paper traces the origins, definitions and drivers of both e-business and online learning systems in the 1990s, showing how e-business principles and strategies in the future will have a beneficial impact on online learning systems, even if online learning systems eventually lose their identities as separate from the rest of the organisation.

An e-business focus for online learning systems would start with an understanding of the customers' needs; would find a customer-centric solution, not a technology-centric solution; would empower the customer; would provide sufficient and multiple types of support for the customer; would provide quality and skilled input; and would provide cost effective, reliable and accessible technology.

This vision of an e-business approach to training varies greatly from the traditional business model for the delivery of training, particularly by VET Registered Training Organisations (RTOs). The traditional business model includes real estate prices dictating location of campuses; architecture dictating class sizes; industrial relations dictating the number and length of sessions and prescribing tight role descriptions; queues of students enrolling in February and July each year; and students seated in teacher-dominated classrooms. In contrast, an e-business basis for RTOs would involve the use of electronic communication to improve business performance, improve the use of existing resources, enhance existing services and increase market reach.

An e-business model for RTOs would include the following features: the development of new relationships with customers, using electronic communication to strengthen the relationship; the pursuit of new student markets; and the development of new relationships and alliances between providers. In this new arena of potential and threat, of disintermediation and reintermediation, there will be new roles for new intermediaries; and there will emerge new ways of supporting teaching and learning. Progressive education and training organisations will realize the potential offered by e-business and enjoy the fruits of reintermediation.
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A new adaptive blind channel identification algorithm

This paper addresses the blind identification of single-input multiple-output (SIMO) finite-impulse-response (FIR) systems. We first propose a new adaptive algorithm for the blind identification of SIMO FIR systems. Then, its convergence property is analyzed systematically. It is shown that under some mild conditions, the proposed algorithm is guaranteed to converge in the mean to the true channel impulse responses in both noisy and noiseless cases. Simulations are carried out to demonstrate the theoretical results.

Channel estimation of dual-hop MIMO relay system via parallel factor analysis

The optimal source precoding matrix and relay amplifying matrix have been developed in recent works on multiple-input multiple-output (MIMO) relay communication systems assuming that the instantaneous channel state information (CSI) is available. However, in practical relay communication systems, the instantaneous CSI is unknown, and therefore, has to be estimated at the destination node. In this paper, we develop a novel channel estimation algorithm for two-hop MIMO relay systems using the parallel factor (PARAFAC) analysis. The proposed algorithm provides the destination node with full knowledge of all channel matrices involved in the communication. Compared with existing approaches, the proposed algorithm requires less number of training data blocks, yields smaller channel estimation error, and is applicable for both one-way and two-way MIMO relay systems with single or multiple relay nodes. Numerical examples demonstrate the effectiveness of the PARAFAC-based channel estimation algorithm.

Multiple perspectives framework to model complex processes

The growing complexity of organisations has resulted in collaboration between multiple stakeholders becoming a challenging and critical issue that organisations must address in order to ensure their practices are sustainable. A multiple-case field study was conducted in order to demonstrate the proposed methodology of analysis and examination for knowledge-based systems in an actual organisational setting. The use of a multiple-perspective framework to improve understanding of the complex relationships in such systems was examined. In particular, the case study focused on the Australian Government’s Nation Building Economic Stimulus Plan (NBESP) which provided $1.9 billion to construct social housing across the State over two years. The results suggest that the use of a multi-perspective framework is appropriate and that there is a need for attention to be paid to the economic perspective.