Research:
Current Research Topics
An overview of WCSP research areas is available in PDF format.
OFDM & Multicarrier CDMA Systems
The enhancement of current OFDM based wireless communication systems and the development of future generation wireless and mobile communication systems based on OFDM and multi-carrier modulation are the main research interests. Focus is on physical layer and MAC layer algorithm development, as they relate to transmitter and receiver adaptation; and improved receiver algorithms, including channel estimation; frequency offset estimation, synchronization, interference cancellation, impairment modeling, and studying the effect of these algorithms on the system.
Wireless test-bed that was completed recently provides opportunities for us to study practical aspects of the OFDM based wireless systems, including PA impairments and PA linearization studies. Also, accurate model of RF impairments are developed using the test-bed and computer aided design tools. The test-bed include vector signal generator and vector signal analyzer for generating custom waveforms and for testing the performance of the baseband transceiver algorithms under realistic radio conditions.
Current Projects
- Covert OFDM communication (Physical and MAC layer security enhancement techniques)
- Blind Modulation Detection
- Noise Power and SINR Estimation
- Synchronization (time and frequency offset)
- Channel estimation
- Mobility and channel variation estimation for the adaptive transceiver design for IEEE 802.16e based WMAN technology
- OFDM based WMAN test-bed for the WiMax compatible product development
- Adaptation techniques in WMAN.
- Self Interference Cancellation (ISI and ICI)
Cognitive Radio
Cognitive Radio is a recently emerging technology based on Software-Defined Radio, and it is expected to provide solutions to numerous wireless communication problems experienced. Advanced capabilities of the Cognitive Radio such as sensing, learning, memorizing, and adapting itself can be used for the following purposes: Optimizing the individual communication performance, increasing the overall network efficiency with which it communicates, increasing the spectrum efficiency, etc.
Current Projects
- Spectrum Sensing
- Waveform Generation for Opportunistic Spectrum Usage
- Spectrum Shaping
- Distributed Cognition
- Cognitive Resource Optimization
- Cross-layer Adaptation
Ultrawideband (UWB) Systems
This research involves the development of new physical layer techniques for the improvement of ultrawideband (UWB) systems for personal area wireless communication systems. Goals include: increasing data rate, improving capacity and system performance, and reducing power consumption by designing simple and power efficient algorithms. Research includes: multi-user interference cancellation; narrowband interference (NBI) cancellation; multiple access techniques and multiple access code design; study/evaluation of modulation options; ultrawideband channel characterization and study of its effect on the system; synchronization, jitter and multipath analysis; and receiver enhancement algorithms, including improved channel estimation, practical and efficient RAKE receiver design, interference cancellation receiver algorithms, etc.
In addition, a generic wireless testbed based on the UWB technology is being developed. This will allow the study of practical transceiver design techniques in realistic transmission scenarios. Also, it will enable accurate modeling of the channel and other transceiver impairments. Energy detector type of receiver architecture is implemented in the UWB testbed as an initial approach. In subsequent stages more complex UWB receiver architectures such as a Rake receiver implementation will follow.
Current Projects
- Time Hopping Multiple Access Sequence Design
- Channel Estimation
- Narrowband Interference Cancellation
- Multiuser Interference Cancellation
- Effects of Timing Jitter on System Performance
- Modulation/coding, adaptive transceiver and system design etc.
- Application of UWB to wireless sensors and ad-hoc networks
- Very short range low power and extremely high data rate wireless transceiver prototype development based on UWB for wireless interconnection between chips for fully reconfigurable architecture
Multiple-input multiple output (MIMO) Systems
Research goal is to study and improve multiple-antenna transmission and multiple-antenna reception (MIMO) wireless communication systems. Issues related to mutual coupling and correlation between antenna elements, multi-user receiver algorithms for MIMO schemes, channel estimation and tracking of multi-channel, synchronization, and frequency offset estimation are among the focus areas. More specifically, our focus is the application of MIMO to OFDM systems (MIMO-OFDM). Currently, the OFDM based wireless test-bed is being updated to test and develop MIMO-OFDM research.
Current Projects
- Dynamics of Spatial Correlation and Implications on MIMO Systems
- Study of mutual coupling effect in MIMO and multi-antenna systems
- MIMO channel estimation
- Extension of OFDM testbed to MIMO-OFDM up to 16 antennas at the Tx and Rx and performance measurements under realistic interference, noise and impairment conditions
- MIMO-OFDM synchronization and frequency offset estimation
Cellular Mobile Radio
Current Projects
- Interference Cancellation
- Adaptation techniques and Enabling Parameter Estimation Algorithms
- XG
- MC-CDMA
Testbed Projects
- Wireless LAN Testbed
- Ultrawideband Testbed
Applications and Standards
- Wireless LANs (IEEE802.11a/b/g)
- Wireless MANs (IEEE802.16)
- Wireless PANs (IEEE802.15.3)
- Wireless Ad Hoc Networks
- Wireless Sensor Networks (IEEE802.15.4)