Research Topics for Ph. D. and Master (by Research) Students
Error Control Coding and Digital Communication Systems
An important function of any modern digital communications system is error control coding. Such coding is the field of
communications that deals with techniques for detecting and correcting errors in a signal. Though used in a variety of
systems, error control coding is especially useful in wireless communications systems. Such systems typically operate
with a low signal-to-noise ratio (SNR) and suffer from distortion because of a multipath channel. The harsh wireless
environment means that the received signal is prone to errors. Research by issues below:
Coding for Reliable Digital Transmission and Storage.
Linear Block Codes.
Cyclic Codes.
Binary BCH Codes.
Nonbinary BCH Codes, Reed-Solomon Codes, and Decoding Algorithms.
Trellis Codes
Convolutional Codes.
Turbo Coding.
Unequal Error Protection Codes.
Mobile Communication Systems
In this work, major issues in mobile communications are addressed. RF electronics: receivers (up/down link) for smart
antenna in GSM900 standard and receiver/transmitter in DCS1800 standard. Transmission channel testing for bit error
rate. Application of Finite Difference Time Domain software for RF/microwave device design for mobile communications
where conventional software like Touchstone is inadequate. PML (Perfect Matched Layer) implementation to improve
FDTD accuracy. Low insertion loss filters for receiver front-end and microstrip dual-mode filters, narrow band Cheyshev
and elliptic filters. Studies of high temperature superconducting thin film properties for base station front-end
applications. Overall objective of this work is to improve signal strength, increase call duration and quality of mobile
communication.
Optical Fibre Communication Systems
Research issues in optical fibre communication systems.
* Operation of optical fibre transmission lines, light sources and detectors, and their application to communication
systems. Light transmission in optical fibres, the differing modes of propagation, and the types of fibre. The physical
properties and operating principles of a range of light sources and detectors.
* Investigate optical fibre transmission lines, Investigate sources and modulating devices used for fibre optic
communication systems, Investigate optical detectors used for fibre optic communication systems, determine the
performance of typical optical fibre communication systems and calculate link budgets.
* Application-Specific Polymer Optical Fibres - Taking advantages of flexibility in synthesising functional organic
materials, fabrication of polymer optical fibres for various applications meeting specific design requirements.
* Application-Specific Planar Optical Waveguides - Using HC-PECVD and HC-RIE techniques, fabrication of low loss
planar optical waveguides for various applications meeting specific design requirements.
* Application-Specific Silica Optical Fibres - Using MCVD technology, fabrication of silica optical fibres for various
applications meeting specific design requirements.
* Optical fibre sensor systems - Developing optical fibre sensor for various industrial applications
* Passive Fibre-Optic Devices - Developing fibre Bragg gratings, fibre couplers, wavelength-division multiplexers, etc.
* Active Fibre-Optic Devices - Developing fibre amplifiers, fibre lasers, optical switches, logic elements etc can be made
from rare-earth doped fibres.
* Light propagation in Optical Fibre systems - Working on optical soliton communication and dispersion managed fibre
systems
* Wavelength Division Multiplexing (WDM) Optical Networks - A large number of wavelengths of light can be sent into a
fibre thus increasing the fibre capacity by the same number.
* Rare-Earth-Doped Planar Optical Waveguides - Optical waveguide amplifiers and lasers can be constructed.
* Optical Waveguide Characterisation - Measurement of waveguide losses and waveguide refractive indices etc.
* Bragg gratings in polymer optical fibre - Manufacture of narrow band wavelength filters
Space-Time Communication
Space-time codes seek to simultaneously exploit spatial and temporal diversity by spreading symbols across time and
multiple transmit antennas before transmission. The two primary approaches, space-time trellis coding and space-time
block coding represent significant steps in a paradigm shift that has taken place in the last several years in which
researchers have begun to investigate transmitter-based signal processing for diversity exploitation and interference
suppression. Space-time trellis codes perform very well, but have high complexity. Space-time block codes, on the other
hand, are important because they allow for simple (linear) maximum-likelihood decoding. Research issues in space-time
communication.
* Space-Time Coding for Wireless Communication
* Coherent and Noncoherent space-time Communication
* Space-Time Coding and MIMO Channels
* Space-Time Coding and OFDM
* Space-time channel modeling and estimation
* Space-time equalization
Multiuser Downlink Beam Forming for CDMA Systems
In modern wireless applications including mobile internet, the capacity of downlink channel shall be higher than that of
uplink channel. From this, there is strong demand to improve the downlink channel capacity. Having multiple transmit
antennas, downlink beam forming is possible. Depending on performance criteria, we can find different optimal weight
vectors for downlink beam forming. In this project, we shall use various performance criteria to find weight vectors. Since
CDMA systems are interference-limited, multiuser downlink beam forming is desirable to provide significant performance
improvement. In addition, multiuser downlink beam forming is related to downlink power control with QoS. Hence, the
QoS and power control shall be also taken into account in downlink beam forming.
Multiuser Filtering for Downlink Channels in CDMA Systems
CDMA systems are interference-limited. In order to mitigate the interference, multiuser detection has been considered
for the last decade. Multiuser can successfully mitigate interfering signals so that the detection performance is
significantly improved. In general, a high complexity is required to implement multiuser detectors. It means that the
mobile handset is hard to have a multiuser detector and, thereby, the downlink performance improvement using
multiuser detection is hard to be realised. From this point, any techniques to mitigate the downlink interference at the
base station are highly desirable. Using filter banks at the base station transmitter, the downlink interference can be
mitigated. Various methods are available to implement the transmitter filtering in CDMA systems. In this research topic,
transmitter filtering algorithms shall be developed. A joint approach with the receiver filtering can be also investigated for
further interference mitigation from other cells.
Vector Channel Estimation for Receive Antenna Arrays in CDMA Systems
It is well known that a better capacity of wireless systems can be achieved by exploiting space domain. However, this
performance or capacity improvement can be only achieved when the channel state information (CSI) is precisely
known. Hence, the vector channel estimation is quite important to obtain the expected performance. Certainly, the
channel vector can be estimated in different ways. In order to have good channel vector estimate, the knowledge of
spatial and temporal statistical properties shall be properly utilized. In this project, structural channel vector estimation
methods shall be investigated. A theoretical performance analysis shall be also carried out.
Other Research Areas
* Speech processing
* Subspace methods in sinusoidal modelling & representation of speech
* Joint estimation of the voiced component and spectrum of a speech signal
* Coding of sinusoidal amplitudes with all pole and pole-zero models
* Wideband enhancement of narrowband speech and wideband speech coding
* Wideband CDMA
* Fast speech classification methods & speech coding using classification
* Voice activity detection
* Sound morphing, auditory scene analysis and auditory masking analysis
* Highly scalable compression of video
* Video transmission over ATM Networks
* A support environment for network consciousness in mobile computing
* Development of a research telecommunication network
* Quality of service management in mobile internet
* A support environment for network consciousness in mobile computing
* Supporting adaptation in network protocols and applications in mobile computing systems
* Mobile aware server architectures
* Architecture for billing and charging in programmable internet
* Discrete Cosine Transform
* Image and Video Processing
* Wavelet Image and Video Compression
* Wavelet Analysis
Error Control Coding and Digital Communication Systems
An important function of any modern digital communications system is error control coding. Such coding is the field of
communications that deals with techniques for detecting and correcting errors in a signal. Though used in a variety of
systems, error control coding is especially useful in wireless communications systems. Such systems typically operate
with a low signal-to-noise ratio (SNR) and suffer from distortion because of a multipath channel. The harsh wireless
environment means that the received signal is prone to errors. Research by issues below:
Coding for Reliable Digital Transmission and Storage.
Linear Block Codes.
Cyclic Codes.
Binary BCH Codes.
Nonbinary BCH Codes, Reed-Solomon Codes, and Decoding Algorithms.
Trellis Codes
Convolutional Codes.
Turbo Coding.
Unequal Error Protection Codes.
Mobile Communication Systems
In this work, major issues in mobile communications are addressed. RF electronics: receivers (up/down link) for smart
antenna in GSM900 standard and receiver/transmitter in DCS1800 standard. Transmission channel testing for bit error
rate. Application of Finite Difference Time Domain software for RF/microwave device design for mobile communications
where conventional software like Touchstone is inadequate. PML (Perfect Matched Layer) implementation to improve
FDTD accuracy. Low insertion loss filters for receiver front-end and microstrip dual-mode filters, narrow band Cheyshev
and elliptic filters. Studies of high temperature superconducting thin film properties for base station front-end
applications. Overall objective of this work is to improve signal strength, increase call duration and quality of mobile
communication.
Optical Fibre Communication Systems
Research issues in optical fibre communication systems.
* Operation of optical fibre transmission lines, light sources and detectors, and their application to communication
systems. Light transmission in optical fibres, the differing modes of propagation, and the types of fibre. The physical
properties and operating principles of a range of light sources and detectors.
* Investigate optical fibre transmission lines, Investigate sources and modulating devices used for fibre optic
communication systems, Investigate optical detectors used for fibre optic communication systems, determine the
performance of typical optical fibre communication systems and calculate link budgets.
* Application-Specific Polymer Optical Fibres - Taking advantages of flexibility in synthesising functional organic
materials, fabrication of polymer optical fibres for various applications meeting specific design requirements.
* Application-Specific Planar Optical Waveguides - Using HC-PECVD and HC-RIE techniques, fabrication of low loss
planar optical waveguides for various applications meeting specific design requirements.
* Application-Specific Silica Optical Fibres - Using MCVD technology, fabrication of silica optical fibres for various
applications meeting specific design requirements.
* Optical fibre sensor systems - Developing optical fibre sensor for various industrial applications
* Passive Fibre-Optic Devices - Developing fibre Bragg gratings, fibre couplers, wavelength-division multiplexers, etc.
* Active Fibre-Optic Devices - Developing fibre amplifiers, fibre lasers, optical switches, logic elements etc can be made
from rare-earth doped fibres.
* Light propagation in Optical Fibre systems - Working on optical soliton communication and dispersion managed fibre
systems
* Wavelength Division Multiplexing (WDM) Optical Networks - A large number of wavelengths of light can be sent into a
fibre thus increasing the fibre capacity by the same number.
* Rare-Earth-Doped Planar Optical Waveguides - Optical waveguide amplifiers and lasers can be constructed.
* Optical Waveguide Characterisation - Measurement of waveguide losses and waveguide refractive indices etc.
* Bragg gratings in polymer optical fibre - Manufacture of narrow band wavelength filters
Space-Time Communication
Space-time codes seek to simultaneously exploit spatial and temporal diversity by spreading symbols across time and
multiple transmit antennas before transmission. The two primary approaches, space-time trellis coding and space-time
block coding represent significant steps in a paradigm shift that has taken place in the last several years in which
researchers have begun to investigate transmitter-based signal processing for diversity exploitation and interference
suppression. Space-time trellis codes perform very well, but have high complexity. Space-time block codes, on the other
hand, are important because they allow for simple (linear) maximum-likelihood decoding. Research issues in space-time
communication.
* Space-Time Coding for Wireless Communication
* Coherent and Noncoherent space-time Communication
* Space-Time Coding and MIMO Channels
* Space-Time Coding and OFDM
* Space-time channel modeling and estimation
* Space-time equalization
Multiuser Downlink Beam Forming for CDMA Systems
In modern wireless applications including mobile internet, the capacity of downlink channel shall be higher than that of
uplink channel. From this, there is strong demand to improve the downlink channel capacity. Having multiple transmit
antennas, downlink beam forming is possible. Depending on performance criteria, we can find different optimal weight
vectors for downlink beam forming. In this project, we shall use various performance criteria to find weight vectors. Since
CDMA systems are interference-limited, multiuser downlink beam forming is desirable to provide significant performance
improvement. In addition, multiuser downlink beam forming is related to downlink power control with QoS. Hence, the
QoS and power control shall be also taken into account in downlink beam forming.
Multiuser Filtering for Downlink Channels in CDMA Systems
CDMA systems are interference-limited. In order to mitigate the interference, multiuser detection has been considered
for the last decade. Multiuser can successfully mitigate interfering signals so that the detection performance is
significantly improved. In general, a high complexity is required to implement multiuser detectors. It means that the
mobile handset is hard to have a multiuser detector and, thereby, the downlink performance improvement using
multiuser detection is hard to be realised. From this point, any techniques to mitigate the downlink interference at the
base station are highly desirable. Using filter banks at the base station transmitter, the downlink interference can be
mitigated. Various methods are available to implement the transmitter filtering in CDMA systems. In this research topic,
transmitter filtering algorithms shall be developed. A joint approach with the receiver filtering can be also investigated for
further interference mitigation from other cells.
Vector Channel Estimation for Receive Antenna Arrays in CDMA Systems
It is well known that a better capacity of wireless systems can be achieved by exploiting space domain. However, this
performance or capacity improvement can be only achieved when the channel state information (CSI) is precisely
known. Hence, the vector channel estimation is quite important to obtain the expected performance. Certainly, the
channel vector can be estimated in different ways. In order to have good channel vector estimate, the knowledge of
spatial and temporal statistical properties shall be properly utilized. In this project, structural channel vector estimation
methods shall be investigated. A theoretical performance analysis shall be also carried out.
Other Research Areas
* Speech processing
* Subspace methods in sinusoidal modelling & representation of speech
* Joint estimation of the voiced component and spectrum of a speech signal
* Coding of sinusoidal amplitudes with all pole and pole-zero models
* Wideband enhancement of narrowband speech and wideband speech coding
* Wideband CDMA
* Fast speech classification methods & speech coding using classification
* Voice activity detection
* Sound morphing, auditory scene analysis and auditory masking analysis
* Highly scalable compression of video
* Video transmission over ATM Networks
* A support environment for network consciousness in mobile computing
* Development of a research telecommunication network
* Quality of service management in mobile internet
* A support environment for network consciousness in mobile computing
* Supporting adaptation in network protocols and applications in mobile computing systems
* Mobile aware server architectures
* Architecture for billing and charging in programmable internet
* Discrete Cosine Transform
* Image and Video Processing
* Wavelet Image and Video Compression
* Wavelet Analysis
