Electrical and Electronic Engineering - Research Publications
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ItemMinimum phase properties for input nonaffine nonlinear systemsNesic, D ; Skafidas, E ; Mareels, IMY ; Evans, RJ (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1999-04-01)For input nonaffine nonlinear control systems, the minimum phase property of the system in general depends on the control law. Switching or discontinuous controllers may offer advantages in this context. In particular, there may not exist a continuous control law which would keep the output identically equal to zero and for which the zero output constrained dynamics are locally stable, whereas a discontinuous controller which achieves this exists. For single-input/single-output input nonaffine nonlinear systems we give sufficient conditions for existence and present a method for the design of discontinuous switching controllers which yield locally stable zero dynamics.
ItemHigh-speed indoor optical wireless communication system with single channel imaging receiverWang, K ; Nirmalathas, A ; Lim, C ; Skafidas, E (OPTICAL SOC AMER, 2012-04-09)In this paper we experimentally investigate a gigabit indoor optical wireless communication system with single channel imaging receiver. It is shown that the use of single channel imaging receiver rejects most of the background light. This single channel imaging receiver is composed of an imaging lens and a small photo-sensitive area photodiode attached on a 2-axis actuator. The actuator and photodiode are placed on the focal plane of the lens to search for the focused light spot. The actuator is voice-coil based and it is low cost and commercially available. With this single channel imaging receiver, bit rate as high as 12.5 Gbps has been successfully demonstrated and the maximum error-free (BER<10⁻⁹) beam footprint is even larger than 1 m. Compared with our previous experimental results with a single wide field-of-view non-imaging receiver, an improvement in error-free beam footprint of >20% has been achieved. When this system is integrated with our recently proposed optical wireless based indoor localization system, both high speed wireless communication and mobility can be provided to users over the entire room. Furthermore, theoretical analysis has been carried out and the simulation results agree well with the experiments. In addition, since the rough location information of the user is available in our proposed system, instead of searching for the focused light spot over a large area on the focal plane of the lens, only a small possible area needs to be scanned. By further pre-setting a proper comparison threshold when searching for the focused light spot, the time needed for searching can be further reduced.
Item8x40-Gb/s Optical Coherent Pol-Mux Single Carrier System With Frequency Domain Equalization and Training SequencesTRAN, AN ; ZHU, CHEN ; DO, CUONG ; CHEN, SIMIN ; ANDERSON, TREVOR ; Hewitt, Donald ; Skafidas, Efstratios ( 2012)
ItemCapacity and Data Rate for Millimeter Wavelength Systems in a Short Range Package Radio TransceiverLiu, C ; Skafidas, E ; Evans, RJ (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2010-03-01)
ItemDesign of 60 GHz millimetre-wave bandpass filter on bulk CMOSYang, B ; Skafidas, E ; Evans, RJ (INST ENGINEERING TECHNOLOGY-IET, 2009-09-01)
ItemFlip-Chip Interconnection Effects on 60-GHz Microstrip Antenna PerformanceFelic, G ; Skafidas, S (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2009-01-01)
ItemCharacterization of the 60 GHz wireless desktop channelLiu, C ; Skafidas, E ; Evans, RJ (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2007-07-01)